Why is that even necessary? Youtube offers you the full list to choose from and I don't see users writhing on the ground clutching their skulls in agonizing confusion. Users can handle a list of languages just fine.
This industry thinks too little of users.
Not true. I'm pretty sure it's licensing cost. In Germany most movies have subtitles only in German, while a handful also in English -- all Netflix originals and maybe some others. Meanwhile, basically all series have English subtitles for some arcane reason.
For me Netflix is a series-only service, I've given up on finding any movie worth watching that would have English subtitles.
For some reason I also get different subtitle options on my phone than I do my television despite both being on the same network (no vpn).
I also hate that they offer a show with audio in the original language, but no subtitles for the same language. So you have to be either mostly fluent or forced to watch the dubbed version.
For the same inscrutable reasons that the film industry insists on schemes like DVD region locking, they are also generally against making a single version of a movie with all subtitles available.