I'm afraid I don't know what German or any other language has done but one obvious point is that not every language has non-gendered pronouns – French for example has only il and elle, masculine and feminine – and some languages, I think, have no gendered pronouns.
Ah the joys of working out the correct version to use of male & female terms too. Le chat, La chatte, the first being the cat (male) & the second being the cat (female). Add in that the same word can have a completely different meaning based on whether it is masculine or feminine, such as Le Tour or La Tour. Then the differentiation in the world of work.. do you just add an 'e' or is it a more complicated case, such as mécanicien / mécanicienne or vendeur / vendeuse, or even facteur / factrice. It confuses me. Add in the obsteuse and ancient machinations of the Académie Française which seems to be strongly opposed to any modernisation of the language, including the use of non-gendered pronouns or any non-gendered words. It feels exceptionally conservative in its views on language.
There have been steps, recently, to de-gender the language (one reason being that occupations deemed to be 'la' are often viewed as inferior, or somehow of lesser importance to one that is 'le' but the Académie has pretty much squashed attempts.
Just a small reason, amongst many, as to why I am not better in use of French language than I find myself. Ending on a positive note, on the local radio station, there is a phone-in quiz where some of the questions are on whether a word is 'le or la' and it came as a surprise to me that so many French people get it wrong too!
There is hope for me yet.