When history looks back on the last 20 years of telecom with dispassionate eyes, I think perhaps the trend that will be most visible is the vast shift in who owns (or wants to own) the physical infrastructure on which communications happen. Look at how different things seem to be evolving.
All of the four top US incumbent providers want to own less stuff than they ever have. They sold their towers already of course. Now they are all looking to unload their data centers. Windstream already has a deal in process, AT&T and Verizon have both been repeatedly said to be looking to sell those assets, and now CenturyLink is doing the same thing. Windstream spun off all its fiber assets into a REIT. And now Verizon is even looking to sell off its global enterprise business and the network it runs on. Other than FIOS, which stalled, and wireless backhaul expansion in-territory, none are spending all that much on building new fiber either.
So the towers are in the hands of tower specialists like Crown Castle and American Tower. The bulk of the intercity and metro fiber is increasingly in the hands of either private equity-backed operators, public nextgen operators like Level 3 and Zayo, or cable MSOs. The data centers are increasingly owned by either the likes of Google, Amazon, and Apple or the colo specialists like Equinix, Digital Realty, CoreSite, Tierpoint, etc. And Frontier has been sweeping up unwanted rural bits and pieces.
Remember when Ma Bell owned it all? From the intercity backbones to the only data centers and interconnection points that mattered all the way down to the rented rotary phone in the hall? There was a time when they didn't want to give up control of *any* of that infrastructure.
Now what is it the incumbent providers all want to actually own? Spectrum, regional but non-rural incumbent fiber and copper where competition is limited if present, and a national backbone to keep things hooked up and the traffic flowing. That and the customer relationship, especially in the case of wireless consumers, who they will fight to the death for of course. Everything else is or probably soon will be in other people's hands.
So with all the consolidation, Ma Bell may be closer to being reassembled than ever but she doesn't quite look the same.
It's a good thing for the industry when ownership lies in the hands of people who like the business of both owning it and investing in more of it even in a competitive market. But the scope of the shift is just staggering when you think about it. The descendents of Ma Bell have either distilled dominance down to just a few key things to own, or else they're selling away precisely what made incumbency worth having. Depends on your point of view I guess.