If they do this, their content creators will leave for another platform.
What other platform?
A bunch left for twitch after the demonetization scandal. A few use exclusively Patreon, but there's no discoverability there.
I will agree there's not a lot of options, though.
How do you ban something like that? If I make a video in which I happen to be drinking a Mr. Pibb, how do you tell the difference between it being undisclosed product placement vs. me being thirsty?
As far as I know they do keep track of videos that have undisclosed product placement, I'm fairly sure I've read that videos that do that are getting demonetised.