The problem, as I see it, may be that only one or two entities have a legal right to build and operate that last mile of connectivity. So, customers are "owned"

The problem, as I see it, may be that only one or two entities have a legal right to build and operate that last mile of connectivity. So, customers are "owned" by one telco and one cable company (maybe two cable companies in some places). Those companies are territorial, even when they are legally bound to share the line. But, yes, more regulation would be one way to solve it. Another way to solve it may have been to not create massive monopolies on that last mile so many years ago, or not allowing those monopolies to simply print money at the expense of consumers and any competitors. I'm not sure about which is the better approach. But, the current approach of government picking one company to destroy all others is a truly awful middle ground.