It’s actually an even worse mess politically than singular they! French is much worse in terms of gender, not only because the translation for plural they is gendered (any group containing something male is “ils”, any group of only female stuff is “elles”), but adjectives are also heavily gendered!
My nonbinary friends I know irl just go for either bc it’s easier. Some people use newly (ish) invented pronouns like “iel” or “ielle” which… I personally don’t like because they don’t fit the phonology very well and they’re a mix of the two instead of a separate thing. Apparently some dialects used to/use “ul” and “ol” which are much nicer imo, but that still leaves the question of adjectives.
Ofc, all this also has the whole aspect of “the wokes going crazy”, plus also France is very against the anglicization (however you spell that) of language and culture so there’s that extra aspect (ironically, the right use “le wokeisme” which is a horrible anglicism, while railing against anglicization).