I don’t think this would’ve happened though if there hadn’t been the societal impetus that aided adoption. The singular they may have been around since Chaucer or Shakespeare - ~30 years ago, people didn’t really use it. There was far more “he or she” going on, that’s now been more commonly replaced with a “they,” also because it’s shorter. English benefits from the fact that the neutral pronoun slots right in to the existing grammar. Other languages struggle with finding such a neutral replacement because it’s more often than not a new word and a slightly altered grammatical function. English is okay on the first problem and arguably okay to mostly okay on the second.