Looks like you found it, but "sponsors" refers to sponsored segments that are part of the video itself.

Sponsorblock is amazing, as it lets you skip not only sponsored segments, but so much more: intros, self promotion, non essential parts of videos, and tons of other things.

That was a truly disappointing video. He spent tons of time yapping about how this freeze-dryer worked, but he didn't once bother to show a simple picture of the phase diagram for water, which makes it completely clear exactly why freeze-drying works.

As for SponsorBlock, it'll block all kinds of things. It's up to you, the user, to not expect software to read your mind, and to learn how your software works so you can configure it the way you want. With SmartTube, you can configure the SponsorBlock functionality to only skip things you want skipped, and not skip things you don't want skipped (such as intros, outros, self-promotions, etc.), or you can even just turn it off altogether if you want. It's really quite simple.