seems very arbitrary that we specify pronouns in a form like "they/them", with the subject and then the object form. nobody changes the case relationships when defining pronouns, so it would be totally clear to just use one form by itself, like just "they" or just "them", and conversely if the goal is to fully specify the format then there should also be a possessive in there, right: "they/them/their"
this is the sort of thing that probably originated in a single place in a fairly arbitrary way, if you could trace it all the way back, but my personal theory is that people didn't want to write out three forms because it's pointless, but they didn't want to write just one because it looked too much like ordinary language. the subject/object formula is distinct in a way that sets this custom apart from direct use of pronouns, or from references to them as words or grammatical units. this also seems to be why we say "pronouns" -- some people are happy with more than one set, but the plural seems to have originated as a reference to this subject/object presentation, which again marks it out as a distinct social tendency, since outside of that context one almost never uses the plural possessive "one's pronouns" to refer to anything other than a language
This has leaked into German too, in which we now declare our pronouns as a set of two arbitrary cases of at least four. Like, nobody says "my pronouns are er/ihn/ihm/seiner and my possessive pronouns are sein/seine/seinen, sein/seine/seinem and seiner/seinen/seines/seiner", which is fine, because I just happen to know how to speak German, but if you like me to use some set of neo pronouns like "dei/deren" it becomes a bit more complicated, because not only have I no direction to what case which word corresponds, there are also far too few cases given to guess a general pattern.
"Ich gehe mit dei spazieren" (I am going on a walk with them) sounds un-flexed but I really have no idea how to form that kind of sentence.
I suppose the correct flexion would be analogous to "them" which of course germanized would be "dem" but "dem" is already Dativ (3rd case) of the masculine definite article "der". Definite articles are used for shorthandedly pointing at objects or people. So saying "Ich gehe mit dem spazieren" sounds more like "I am going on a walk with that guy over there" rather than "I am going on a walk with them".
So this was my boomer-esque rant on German neo pronouns.
in the English case I always assumed it was becsuse, when spoken, "my pronouns are he" and "my pronouns are she" can be difficult to tell apart in a noisy room. "he/him" and "she/her" provides better discernment





















