That's a real problem for sure, but I'm not a fan of the solution.
They should have been found guilty of anticompetitive behaviour and split up into multiple companies.
Here in Australia we've gone down that path though there was no actual lawsuit. We just saw problems starting to creep in and dealt with it proactively. The vast majority of network infrastructure is now owned by a company called "NBN Co" (National Broadband Network) which is required to provide the best available network technology to every single household/business in the country. All pre-existing network operators were forced to sell their infrastructure to NBN Co and any business can provide services to anyone for a reasonable fee paid to NBN Co. Mostly it's broadband internet, but literally anything can go over the pipes. The fee varies depending on the bandwidth and QoS level.
They are also investing in network upgrades, including state of the art DSL routers that can run at decent speeds for most people (I get about 80Mbps) and all new connections are Fibre as well as existing connections are gradually moving to Fibre (on those, you can usually get 10Gbps). Each building can have multiple connections, at least four but large buildings obviously get more. If you live in the middle of the desert with no wired networking at all, then you get a wireless one. Satellite if necessary, though usually it will be "fixed wireless" which is basically cellular with large/high quality a rooftop antenna.
NBN Co is tax payer funded, but mostly only to accelerate fibre installations. Aside from that upfront capital expenditure it is profitable and some of those profits are paying off the tax payer's uprfront investment.