I'm not saying creators shouldn't diversity their income streams. My first comment in this chain was pointing out that Youtube isn't urging creators to embed sponsorships, which copperx seemed to think Youtube was doing.
Youtube is widely known to demonetise videos and outright kill established channels based upon spurious inputs / phase of moon / etc. The recent Russell Brand stuff easily springs to mind, as does abuse of the Content ID three strikes policy by bad actors.
If the creators need their income to be resilient to demonetisation, they're forced to use options outside the Youtube system. Sponsorships, etc.