Earlier quoted context omitted.
The regulators could have forced the big four carriers (now three) into a common carrier model. In that setup, all cell providers would effectively be an MVNO, and the three (then, four) physical networks would be operated at arms length from the consumer facing side. Also, the four networks could be structured so that their financial incentives were to improve cell coverage and bandwidth instead of undermining each…
The best way to resolve these issues is never "force the bad guys to do good things" but rather destroy the walls which enable their rent seeking. Regulators can work to make it extremely simple for new techs in this space to come up so there is real competition for ATT etc.
All kinds of more experimental community networks make use of it. Even better, Magma core is a free 5G core and multiple vendors like Baicells make cheap 5G CBRS base station hardware. CBRS also fully overlaps international 3.5GHz 5G bands, so phones and modems are cheap.