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.