A quick Google says you’re wrong, I’m not an accountant for YouTube so I couldn’t prove otherwise. Presumably if there was zero benefit to creators, they would all turn the adverts off, rather than just some of them.

I’m aware that they only get a small percentage of the ad revenue but it’s like that in every business unfortunately. When I buy a loaf of bread at the supermarket, I know that only a tiny fraction of a percent the price will go in to the checkout worker’s or farmer’s, or the baker’s paycheck, but I’m not going to boycott supermarkets because of that.