We will need bigger rockets for bigger satellites if you want multiple providers to add their own antennas to the same satellites and provide enough bandwidth.

Another option would be some world entity managing the singular satellite internet, and everyone becomes a virtual network operator on that network like a MVNO on the cellular infrastructure. So one set of standard infrastructure. 1 antenna for everyone not 5 antenna for 5 companies.

You end up with a law that says the person running the hardware can't run the services. I wish they'd pass laws like that for our land based infrastructure.