Is there? How are we defining value here? Profit?

I broadly agree that creators hugely benefit from these platforms, but that really doesn't seem to be what they're optimizing on imho. And you basically admitted they're a monopoly with that final statement.

It costs money to host video. The volume of advertising you sell supports your costs, with a fraction going to the content creators. Using information you gather increases how much advertising you can sell. The more advertising you sell the more money everyone gets.

Having a low cost infrastructure for video streaming and good advertising deals is not a monopoly, it's an investment.

But you can still have advertising, just not targeted and use tactics from the gaming industry to get people hooked on content.