> it obviously prompts a lot of people to install sponsorblock

I would be very surprised if more than 1% of YouTube viewers use sponsorblock.

> I do think more people would subscribe if sponsors would be blocked on premium.

Definitely agree there!

> It would be great to see less sponsors

You wouldn't see that though. It's pretty clear sponsors pay waaay more than advertising. Creators would just integrate them more into the video so there's nothing to skip. Like instead of "this segue to our sponsor ComfyPants", it would be that their username in the game review is ComfyPants, and they get a skin only wearing pants, and they do the review wearing ComfyPants... you get the idea. Much worse.