The big one is Amazon. The revenue from AWS funds the ability for them to crush the high street on the shopping side. They should be forced to sell off AWS as a separate company.
This is all beneficial for the consumer, no? Having a competitive advantage is not illegal. Someone correct me, but isn't the law's intent to protect people from abuse of monopolistic power? Which wouldn't be the case here.
Lately, the outlook of protecting consumers has won out in the US, as that is what the Supremes laid out as a determining factor in the later half of the 20th century.
But it wasn't always that way. And the laws aren't written that way.
In my opinion, focusing on consumer benefit is a red herring. We are all both consumers and producers. An economy full of companies shutting out competition through market manipulation may be good when I'm trying to buy something, but it's bad when I'm trying to find work, because they can dictate whatever terms they desire in that half of my participation in the economy.