That doesn't include all of the transcoding and alternate formats stored, either.
People signing up to YouTube agree to Google's ToS.
Google doesn't even say they'll keep your videos. They reserve the right to delete them, transcode them, degrade them, use them in AI training, etc.
It's a free service.
It is bad enough we can deepfake anyone. If we also pretend it was uploaded by you the sky is the limit.
None of which overrides what the law says or can do.
> It's a free service
I've paid for it. Don't anymore, in large part because of crap like this reducing content quality.