Mardee, there are two things in your comment that I want to address: one is about the centralisation of German as a language/the amount of 'control' over its change, and the other is about the speed of that change. (And I don't at all mean to be difficult! Just I am passionate about my language, so I enjoy discussing it. Please do not take offence!)
About central control: Yes, it is true that there is a spelling commission, and yes, we do have the Duden (the dictionary) that makes recommendations of a sort (like with Gendersprache, the debate you reference). But, and as demonstrated by that debate, there is often massive discussion about their various suggestions, and they are not universally accepted (here is an article in German for those interested in the debates). In the case of the Rat für deutsche Rechtschreibung (the spelling commission): it is important to note that it is explicitly about orthography, not about the language integrity (a term I have questions about, to be honest) more generally. And, even on this restricted level: Just look at the example of the spelling reform of 1996 to see what a gigantic mess this has been at times (the English-language wikipedia article gives a good overview of the disorderly process).
I do understand that, in comparison to English, the idea of any spelling reform of any type makes German seem wildly centralised and controlled (and I am not denying the relatively higher control), but - and this brings me to the point about the 'unchanging-ness' of German - it is at the same time a very good example of how the so-called unchanging-ness of German is actually a mirage. In the case of the spelling commission: our orthography is so transparent because of changes over the centuries, not in spite of them. (Note: I was just today reading a German text in the original form from 1860, and ... even just that far back, there are strong, marked changes in grammar, lexicon and orthography).
About language conservativism in general: there is much debate about how to measure this, though it is true that grammatically and on a long time-horizon, German is considered conservative. At the same time, phonetically speaking, English is actually more conservative than German (it has retained older features of Germanic phonology), so there is that. And, even though there are many grammatical features that are conservative in Standard German, we nevertheless have all sorts of changes that have and continue to happen in our language. At the moment, for example, one might name Anglizismen, or English words used in German, as leading to a wide-spread set of changes in the lexicon. There are literally thousands of terms that we now use every day that were simply not part of our vocabulary at all when I was a child. And just like in any language, grammatical rules are always also in flux, even if over the long term they have shifted more slowly than in other Germanic languages (Genitive vs. Dative usages for example).
And all of that is before we even begin to talk about Dialect, which is part of most native-speakers people's language experience in Germany, even today. For example, I have a migration background, so I didn't learn a dialect directly from my parents, but I do know rather well the one from the area I grew up even so. One cannot leave out the question of dialect or regional language inflection when speaking about the German-speaking area more generally, and it is a story that pushes hard against the narrative of the German-speaking space being somehow linguistically orderly.
I hope this is helpful.