> If you pay for the service, there should be no ads, so that's not an issue.
IIRC, at least Netflix and Spotify have a "pay less, but get some ads" tiers, and YouTube doesn't want SponsorBlock et al to impact the golden geese too much.
> As for artists trying to push their own listing ratio, why would that matter
People have scammed streaming services for millions of dollars [1]. Sure, at their scale it's peanuts, but still eyewatering sums of money for normal people.
[1] https://www.gzeromedia.com/gzero-ai/the-10-million-spotify-s...