Sponsorships are definitely the highest if a youtuber actively engages in them, ad revenue vs patreon depends highly on if you have i.e. a small but highly active fanbase of core fans, versus a wider more general audience that you entertain a bit.

I think people should be more aware of the perverse incentive of YouTubers saying, "my guaranteed source of income is very little and unstable guys, I need you to also subscribe to my patreon" where - could YouTubers perhaps have a reason to act like their ad revenue is very little? In my experience, while ad revenue isn't great, for any decent-size YouTuber its still enough to live on and in any case it always stays a significant income stream.