I've heard this argument before (and recognize that you aren't defending it), but telecommunications, network and technology innovation has hardly suffered since Bell was dismantled in 1982.
Fiber rollout in countries where a government funded phone line rollout has already succeeded is laughably slow, taking decades and many billions with little to show for it. Even in countries where no phone lines were rolled out back in the day, fiber is more and more being skipped as 5G allows for cheaper (though less reliable and less capable) deployment.
I'm not saying monopolies are good or anything, and I think our problems would be even worse had we stuck to the monopolist systems that brought us telecoms as we know it, but I wouldn't consider the industry one where there's enough competition to drive innovation, especially since at least half of the entire sector is competing against Chinese government-controlled companies with seemingly endless coffers.