Which btw doesn't work. Users have to first watch the video, identify "sponsor blocks" and then update the blocker's database. So between the Sponsorblock users who have to watch the video and the multitudes who don't even know it exists... Sponsorblock won't block many sponsors.
Yes it's crowd-sourced, so of course it's not perfect. Saying it doesn't work isn't true though, and as more people get onboard, improves. I don't think it's the final solution, but it helps right now.
