I believe people should be paid for their time and effort. It's probably not sustainable to be regularly shooting and uploading videos on the side of a 9-5 job, and getting paid from videos allows people to focus on making them. Doesn't necessarily need to be ads or sponsors, but at the moment, it seems to be how it goes. At least sponsor segments aren't privacy invasive (unlike YouTube ads, probably).
If you're directly contributing to someone's money-making through different means, like Patreon or Nebula or whatever else, then I think SponsorBlock can be justified. In fact, it'd be interesting if SponsorBlock or something similar allowed people to directly contribute to creators in exchange for skipping sponsors.