Yes and no.

See, ever since youtube started bitching about ad blockers, I've started running it in private mode browser windows only.

The thing about recommendation systems is that they're trained by all users collectively. If you suppose that a specific demographic starts using private mode en masse, well, their contribution to the recommendations is going to be eroded out as well

Think of recommendations like dirt paths. They only remain paths if you keep using them.

Yes and no.

See, ever since youtube started bitching about ad blockers, I've started running it in private mode browser windows only.

The thing about recommendation systems is that they're trained by all users collectively. If you suppose that a specific demographic starts using private mode en masse, well, the system is going to have increasingly bad data about that demographic and what string of videos they navigated to.