AIUI the VTuber scene is very YouTube-centric compared to most other streaming subcultures, so it's easier said than done in this case. If they're doing this professionally (or trying to) then they need to be where the audience is.
The ones I’m aware of stream primarily on Twitch with YT for clips.
If only one company exists that can pay people to perform your role, and that company capriciously locked random employees out of all systems over a misunderstanding, and it's seemingly impossible to start up a competitor or find any other way to get paid doing it... maybe find another job?
I think "streamer" is one of those cases where it's least true.
> The action isn't "quit preemptively", the action is finding another job now, instead of making some other investment you would With your time today.
The action is finding an entirely different career which is a lot more obnoxious than finding another job normally is.
Sometimes risk is less bad than the alternatives.