There's about 10 sponsors that go over and over in the channels I watch. I've seen them all and am a customer of one (from long ago - so nothing to do with their YT sponsorship) already. Nobody benefits from wasting my time showing me products/brands I already know about and already made a decision to buy or not to buy.
Getting rid of tiktock-est YouTube shorts or whatever they call it. Hated having that on my YouTube homepage and the official app doesn't let you remove it. YouTube Vanced does. I also pay for YouTube premium.
Also sponsorblock which is a must for some people.
And picture-in-picture mode was great. I could watch the news while seeing how close an uber was to me without having to switch apps.