One by one the big (but not massive) online services are being framed as instruments of policy:
The massive services are too, but they can afford to play the long game. They are steering it, after all.
… if you don’t like it you can just set up your own company! Well maybe, but when that happens, the monopolies rush in to defend their monopoly. Parler being a good example. This was set up as an alternative to Twitter, but when it got too popular their ability to trade was quashed by Big Tech - the app was removed from the main places people go to get apps, and the big cloud servers would not host the fledgling company’s services.