Honestly I think a lot of things in life would shake out properly if Most Favored Customer clauses[0] were made blanket illegal by large marketplace aggregators. So that would be stores, visa, costco, walmart, ebay, amazon, uber, etc. I think they are the fairly key lynch pins that make these abusive relationships work with larger market players leveraging their position against smaller ones.

With no more MFC clauses, retailers can charge a flat out %3 tax to all credit card users and pass the fee down properly to incentivize them to not use credit cards. Restaurants can list on doordash with the extra fees baked into prices. A %10-30 discount might be enough to incentivize people to call in, etc.

I'm not a law maker, so I don't know how many industries would be screwed up by this. Does anyone think making MFC clauses illegal would screw over society or industries other than organizations that abuse them? Are MFC clauses needed because otherwise useful services would die from prisoner's dillemas? A classic one is the 'maid on order' or 'dogwalker on order' kind of startups because people collude and quickly just create a direct relationship to save money, and you lose benefits like getting ratings and other such things. It makes me wonder.

[0] https://en.wikipedia.org/wiki/Most-Favoured-Customer_Clause