This really needs to be configurable on a per-account basis. I'm using YouTube mostly on mobile devices and TVs, without the possibility to use addons.

The required settings are quite simple (a lot of social media platforms have them): Setting a list of languages that should never be translated, and setting a preferred language the other ones should be translated to.

I guess the silicon valley people who develop YouTube can't grasp the concept that there are people out there who speak multiple languages.