How can one include all people in one's written and spoken language irrespective of one's gender identity(s)? [closed]

I agree with John Lawler's comment: use everyone or anyone. They are inclusive and simple -- so simple that they don't need a dictionary definition in an ELU answer, and so inclusive that they don't leave anyone out. Oops, now I have defined everyone by using anyone: so, I will include a dictionary definition. Merriam Webster say that everyone means

every person

M-W says anyone means

any person at all

(I am not going to give a dictionary definition of every and any.)

These two words, everyone and anyone are correct and instantly comprehensible. In a comment, the OP says that these two words "don't go down well because of lack of specificity", but that is the nature of a general, all inclusive term.

If the OP is writing a paper, he can give an extended definition once, at the beginning, for what he means by everyone; e.g. all members, without exception, of the species homo sapiens.

The trouble with trying to come up with a word or phrase listing what you mean by everyone for repeated use in a paper or article, is that it will be clumsy -- klugy -- and will interrupt the flow of the paper. Ditto in speech. Moreover, you will leave someone out, and that someone, even if in a class of one, will be offended.