After deregulation, In all EU countries there is an "infrastructure manager" (IM) They are responsible for maintaining and expanding the telecom infrastructure. They charge ISPs for using their infrastructure. The ISPs buy this capacity and resell to individual consumers.
Why does this work? The IM is ONLY responsible for infrastructure and it's in their interest to fulfill the market need for more capacity if such a demand exists. Thus it's in their interest to EXPAND coverage and infrastructure because that's how they make money. They're a regulated monopoly.
In the US...
The monopolies (AT&T, Comcast, Verizon) are responsible for both expanding infrastructure AND selling access to end-users. This means that it's in their interest to sell as much end-user service as they can, using the least amount of investment possible. It's not in their interest to expand capacity, unless someone kicks them in the ass because of a lack of capacity.
NB. In the EU, the IM can be an old state telecom that has been privatized. Sometimes a part of the company is also an ISP, but the accounting books must be separated. This type of deregulation works a lot better in some countries than others. The system is not perfect, but IMO it's a lot better than the one in the US.