Obviously, the far-right takes it to an extreme level, even replacing Internet with Weltnetz, but even in the left-wing there’s no opposition to replacing words, or simplifying the language.
And most of these examples are in the common dictionaries, used in major newspapers, will be accepted in your high-school German tests (as long as you use them appropriately and spell them correctly) and are used or at least easily understood by all native speakers. The others fell out of use over time.
Recommendations by various authorities on what constitutes "good" use of language change, and in Germany there might be more reliance on the big dictionaries (but I honestly can't accurately gauge how this compares to various parts of society in English-speaking countries), but actual language use does not care all that much. The reforms and the dictionary are very relevant for spelling and grammar, but have not much influence on actual selection of words, even less in specialist subjects.
People try to change language use with all kinds of motivations all the time, but they can't do much more than suggest, individuals and organizations decide what they agree to and what they don't. And this exists in other languages just as much (trying to avoid offensive terms, trying to sound modern, trying to remove foreign influences).
Half of the words in above list were invented by one single person.
And that person has pushed all of those words into popular use by cooperating with other authors, writers, newspapers at the time.
So, yes, that stuff is possible.
> but they can't do much more than suggest
Except, the authorative dictionaries have authority in Germany because, per definition, tests in schools have to be graded based on them, and official communication of companies has to be written with them.
If a dictionary says "deprecated", these have to switch.
Which, in turn, has a direct effect only a 13 years later (the maximum time it takes someone to go through school).
Change through collaboration and use is exactly what you argued against: a new term is coined, used first by "experts"/influential people, then goes into widespread use and is codified in dictionaries. Right now we can watch a group of people establishing "serverless" as a word for some kind of PaaS in technical language, as stupid and confusing we might think it is (I personally hate trend and would prefer the word be used for P2P or client-side applications, but I think that ship is sailed). Documentation of expert language will soon pick it up, if it hasn't already.
For purposes other than spelling and some grammar rules, dictionaries are nice suggestions, but even in school (where the Rechtschreibreform actually has legal "power", even if it doesn't anywhere else) a word not being in the Duden didn't mean it didn't exist (and conversely, just because it is in there doesn't mean it's good to use). Professional usage has its own conventions (newspaper styleguides, common terms and ways of writing in scientific disciplines, "PR speak"), even if they make for "worse" language, common usage varies even more. And nothing actually enforces language in all those areas, which make up most of our language use. On the contrary, it's used as input for new iterations of guidelines and dictionaries.
Spelling and grammar has been "designed by committee" and relatively successfully legally enforced, the words used are not. They are influenced by motivated groups, but that's part of the linguistic discription model just as well.
We’ve renamed Camouflieren to Tarnen, and many other words like that.
There’s hundreds of cases of words being entire replaced.
A list of replacements of the past centuries, for example: Distanz → Abstand, Liberey → Bücherei, Moment → Augenblick, Passion → Leidenschaft, Projekt → Entwurf, Addresse → Anschrift, Korrespondenz → Briefwechsel, Komödie → Lustspiel, Dialekt → Mundart, Orthographie → Rechtschreibung, Journal → Tagebuch, Autor → Verfasser, Fundament → Grundlage, Antike → Altertum, Parterre → Erdgeschoss, Universität → Hochschule, Terrorismus → Schreckensherrschaft, Singular → Einzahl, Plural → Mehrzahl, poste restante → postlagernd, Coupé → Abteil, Perron → Bahnsteig, Billet → Fahrkarte, Retourbillet → Rückfahrkarte, download → herunterladen.
And even today there are large companies even funding groups working on replacing parts of the language, be it to replace foreign words, or to simplify words: https://www.rossmann.de/unternehmen/soziale-verantwortung/so...
Obviously, the far-right takes it to an extreme level, even replacing Internet with Weltnetz, but even in the left-wing there’s no opposition to replacing words, or simplifying the language.
And even those opposing those changes (see criticism section here https://de.wikipedia.org/wiki/Reform_der_deutschen_Rechtschr... ) don’t oppose these concepts in general, just would rather like to see different changes.