The ideal scenario is, YT takes a fee like they do with Premium for hosting and discovery. The content creator can choose to take a cut if he wishes or can just do his own monetisation. It is upto him, whether he does no monetisation, puts merchandise links in description or outright shows the product in between a video. YouTube can make other integrations for content creators to monetise but they should have freedom of their own as well.
The good thing about competition is, if some content creator is being obnoxious with promotions or product placement, users can find someone who is doing a better job.
In the past some YouTubers have noted that they get more dollar return from a premium viewer watching their video than an ad one, so content creators can choose to forego on promotional placements and compete on a better experience.