I think that a lot of the same problems exist in generic brands at supermarkets. Supermarkets already have a lot of ways to pressure suppliers, and “own brand” products are weaponised extensively.

I’m all in favor of suppliers competing with each other, as that’s in the best interests of society overall. But when the platforms/marketplaces themselves participate in that competition they have tremendous advantages, which is anti-competitive, and it benefits no one but themselves.