It wouldn't be the consumers, but these companies. There's a thing called regulatory capture (https://en.wikipedia.org/wiki/Regulatory_capture).

Try to introduce such regulation, and what would happen is that the regulations themselves would be even manipulated or even drafted by the big players in the market.

Why is that so bad? Because it means the regulations will be harsh to everyone else who tries to join that given market.

This happens all the time in other industries. We don't need this in computing, please.