I dunno, it makes conceptual sense. Networks infrastructure is largely commodity utilities where duplication is effectively a waste of resources. e.g. you wouldn't expect your home to have multiple natural gas connections from competing companies.
Regulators have other ways to incentivize quality/pricing and can mandate competition at levels of the stack other than the underlying infrastructure.
I wouldn't expect that "only a single network" is the right model for all locations, but it will be for some locations, so you need a regulatory framework that ensures quality/cost in the case of a single network anyway.
IMO this can be neatly solved with a peer-to-peer market based system similar to Helium
https://www.helium.com/mobile.
(I know that helium's original IoT network mostly failed due to lack of pmf, but idk about their 5G stuff)
Network providers get paid for the bandwidth that flows over their nodes, but the protocol also allows for economically incentivizing network expansion and punishing congestion with subsidization / taxing.
You can unify everyone under the same "network", but the infrastructure providers running it are diverse and in competition.
Regulators have other ways to incentivize quality/pricing and can mandate competition at levels of the stack other than the underlying infrastructure.
I wouldn't expect that "only a single network" is the right model for all locations, but it will be for some locations, so you need a regulatory framework that ensures quality/cost in the case of a single network anyway.