There is a difference there in that the sponsorship money all goes to the content creator, rather than to YT who may or may not (at their whim) share a small portion with whoever posted the video (which is far from always the content creator).
They also aren't stalking you around everything you do on the Internet in the name of targetting.
No doubt. YouTube premium customers are just providing disposable income data to advertisers. They've segmented the market, it's only a matter of time before some manager looks at how much more valuable the premium group is and decides to show ads to them too because doing otherwise is leaving money on the table.