To be clear: I completely believe that Premium is a major source for many people. 100%. I just haven't seen many examples of it, outside tubers that have zero sponsorships (because they're small and/or not doing the low-value slightly-shady ones that get spammed everywhere). I'm thrilled that Premium seems to pay relatively well, it's better for everyone to move away from ads where possible.

LTT though is a rather significant outlier in terms of subscribers (16.6 million right now). For truly large channels it's reasonable for the equation to be different.

And the equation for them really is different. They're a company with ~100 employees¹ and YouTube and video sponsorships came out to just 11.6% (ads AND premium) and 9.2% respectively of their multi-person company income. People claiming "SponsorBlock steals from creators" aren't talking about LTT, they're talking about smaller creators for whom YouTube stuff is a majority of their income.

Plus, like. Ads+premium lumped into one. It wouldn't surprise me if premium was lower than sponsorships.

1: https://en.wikipedia.org/wiki/Linus_Media_Group