First, it is important to understand the background of this problem: Once upon a time, the Old English language had grammatical genders just like the German language, to which it is closely related. The general female suffix was "-en" in these times, just like the German "-in" today. Thus, for example, a female user is a "useren", and a female trader is a "traderen", just like "Nutzerin" and "Händlerin" in German. This is the basic principle in both languages, besides all grammatical specialties.
These female forms got lost over time in the English language, and what remained were the masculine forms. Now, this simply means that almost all the English nouns of today are grammatically masculine forms! Yes, indeed: baker, butcher, officer, manager, teacher, trader, user, soldier, member, etc. are all grammatically masculine forms. It's always -er, -er, -er, and not -en, -en, -en. The English language is characterized by an obtrusive masculinity, so to say.
Of course, we were always told (by old white male grammarians) that the English nouns "lost" their masculine meaning. They are still grammatically masculine for 100% (there is no doubt about this), but they allegedly lost all their masculinity without any traces of masculinity left. This is the traditional, the conservative explanation of the phenomenon.
This explanation is not credible! Because this is exactly the same what old white male grammarians say about the generic masculinum in the German language: They say that in the statement "die Mitarbeiter" female colleagues are not only "mitgemeint", but that the generic masculinum itself has no specific masculine meaning, despite its grammatical masculinity. In other words: What is known as generic masculinum in German, is in fact everywhere in English: The English language knows only generic masculina: While almost every noun of the English language is grammatically masculine, it is (allegedly) neutral in its meaning!
For the German language, studies reveal that the grammatical masculinum indeed carries over a certain masculine meaning to the generic masculinum. For the English language, everybody knows without any study that this is true, too: We all have experienced the moment of surprise, when we have read some lines of an English text and then suddenly encounter a "she", and at once it becomes clear: This text is about a woman!
It is simply not true that the English language "lost" its gender awareness completely! Gender is very much alive even in explicit form: E.g. in pronouns like "he", "she", "it". And not all nouns lost their gender. Quite a few nouns still have a gender, such as "waiter": A female waiter is still today not a waiter, but a waitress. Or there is the generic masculinum "he" used for a person of unknown gender, just like in the German language. This generic masculinum "he" did not drop out of fashion in the Middle Ages, this happened only in recent years, and only in certain milieus! There is still sufficient gender awareness left in the English language to carry over a certain masculine meaning from the grammatical masculinum to allegedly gender-neutral nouns.
Why do supporters of a gender-sensitive language believe that the obtrusive English masculinity is not a problem at all, and that English nouns really lost all traces of their masculine meaning despite their obvious grammatical masculinity ... while at the same time they do not believe this for the generic masculinum of the German language? Because it's just the same phenomenon: The words are grammatically masculine, but allegedly not masculine in their meaning. For of course, a certain masculinity is carried over from the mere grammatical masculinum to the allegedly gender-neutral words!
But this self-contradiction is ignored by supporters of a gender-sensitive language. This ignorance is very unconvincing and downright illogical. While you say "baker" in the English language, you say "Bäcker*in" in the gender-sensitive German language. Think about it: It is just the same word! "Bäcker" and "baker" is just the same, but in one language it stays "baker", in the other it is modified to "Bäcker*in". Very strange.
It becomes even more strange with words derived from the Latin language, e.g. "administrator". The "-or" suffix is an obviously masculine suffix, and many languages have preserved a female form for it, e.g. "amministratore" / "amministratrice" in Italian, and "administrateur" / "administratrice" in French, and of course "Administrator" / "Administratorin" in German. But the English language knows only "administrator". You just cannot imagine a more obtrusive masculinity! While German gender-sensitive language modifies to "Administrator*in", English just stubbornly stays with "administrator". The obtrusive masculinity of the English language cannot be overlooked.
When consistently applying the same approach of gender sensitivity to all languages, you just cannot ignore the traditional obtrusive masculinity of the English language. Therefore, it would be only consequent to apply the same methods applied to the German language to the English language. For of course does the grammatical masculinity of English nouns carry over a certain masculine meaning to these nouns! If you believe this for the German language, you cannot do otherwise for the English language.
Under this perspective, the solution must and can only be the revival of female forms in the English language in order to break its obtrusive masculinity. No, this is not a far-fetched idea. Because it's quite easy, and because such a revival of ancient forms has already taken place for the sake of gender sensitivity: As everybody knows, supporters of gender-sensitive language have put forward the idea that the pronouns they/them in older English were (allegedly) applied to singulars, too, and so they revived these older English pronouns for our modern times. Yes, such a revival of ancient forms has already happened! Just the same can be done for the female forms. And it's easy: Just adding an "-en", like the "-in" in German. Everybody can do this! Just "useren" or "traderen" for female users and traders. And there is no need to revive the complete older English grammar with all its specialties: This has not been done for the older English pronouns they/them, either.
And as a second logical consequence, the gender star needs to be introduced into the English language. While in German it is "Nutzer*in" or "Händler*innen", it is "user*en" or "trader*ens" in English. This looks great, doesn't it? So easy and such a great improvement under the perspective of gender sensitivity! And when translating texts between the two languages, the similarity of gender forms in both languages will make it all easier! Also speaking the gender star can be done easily: It's just a simple glottal stop, like in German.
Please don't say now that this is very artificial and not natural! Don't say that this is ugly and an assault on your linguistic aesthetics. And don't say that this is just not practical. Because this is the way the German language is currently gendericrucified. And if it's good for German, why shouldn't it be good for English?! Stay positive! Keep smiling!
But wait, there is of course another possibility to deal with the problem. Irony off!
Instead of adjusting the approach of gender sensitivity applied to the English language to the approach applied to the German language, the adjustment could be done the other way round. Even if there is some masculinity carried over to the allegedly gender-neutral nouns from their grammatical masculinity, is it really justified to apply such severe modifications of the language? Modifications, which are very artficial and really not natural. Modifications, which are ugly and an assault on our linguistic aesthetics. Modifications, which are simply not practical. Is such a gendericrucification of our languages really justified and wise? No. Clearly not.
And maybe it is true what the old white male grammarians said about the English nouns, and there is indeed not much masculinity left in them, though they are grammatically masculine without any doubt, and though there is some masculine meaning carried over to them from their grammatical masculinity. This may be true for the German language, too: Although in certain Western German milieus, the awareness of gender neutrality of the generic masculinum has crumbled in recent decades, polls reveal, that most Germans still live with the awareness that the generic masculinum has no exaggerated one-sided masculine meaning which would justify any action. Therefore most Germans stubbornly prefer it over gender-sensitive language modifications although they are generally in favour of equal rights for both genders.
In Eastern Germany this awareness is preserved even better. E.g. eastern German female construction workers say about themselves: "Ich bin Bauarbeiter", or eastern German female doctors say: "Ich bin Arzt". They don't say "Bauarbeiterin" or "Ärztin", as some (not all) Western Germans say, and they say it with pride! They even consider it an insult to call them with the female "Bauarbeiterin" or "Ärztin", since the generic masculinum "Bauarbeiter" and "Arzt" has no masculine meaning at all for them, just like nouns in the English language, and attributing a different (female) form to them provokes the feeling that they are not treated the same as their male colleagues. Also German Bundespräsident Frank-Walter Steinmeier avoids gender language and consequently uses the generic masculinum, e.g. in his programmatic speech on 28 October 2022, in which he prepared the Germans for coming hardships ("Bürger", "jeder einzelne").
If you really want to create more awareness for both genders in the German language, naming both genders at once would be the much better solution (e.g. "Händlerinnen und Händler", "er oder sie"). This method does not need brute force and does not violently turn against the language as it naturally developed. It is also of more beauty and elegance.
Of course, you cannot point to both genders all the time in a text, this would again give an impression of obtrusiveness. On the other hand, attention and awareness for both genders is certainly created much more effectively, if you name both genders more rarely and therefore unexpectedly. We already mentioned the well-known effect in English texts when suddenly an unexpected "she" appears and surprisingly makes clear: It is about a woman. Similar effects can be achieved in the German language with the generic masculinum.
Thus, intelligently interspersing the naming of both genders at once in a text is a challenge and an art. The way how you do this shows your esprit and your intelligence and is the complete opposite of the brute force approach of an obtrusive gendericrucification of our languages as the pseudo-educated and the less-than-great minds of our "modern" world want to have it.
Last but not least, it may be revealed that there never was a singular they/them in older English. Its "revival" is a hoax created by the supporters of a gender-sensitive language. Therefore, the first serious attempts to introduce a gender-neutral singular pronoun suggested e.g. "ou", "it", or "which", but not they/them.
There were only sentences with a subject in singular but of plural meaning with a they/them. Therefore, these they/them had in truth no singular meaning, but a plural meaning. Examples: "There's not a man I meet but doth salute me / As if I were their well-acquainted friend" (William Shakespeare, A Comedy of Errors, 1623). So "not a man ... but" means here: all the men = plural. Or: "Every fool can do as they're bid." (Jonathan Swift, Polite Conversation, 1738). So "every fool" means: all the fools = plural.