> I might not understand the context: decoupling the "cable" from the "provider" is not common in the US, or there are some other complexities that I don't understand?

So the US context in a nutshell; in most places, the provider of the cable is the provider of the service.

In a bit more detail. Up until 1982, almost all telephone service was provided by AT&T (also known as the Bell System or just "The Phone Company"); at that point, it was split up through anti-trust into regional local phone companies (the baby Bells, ex Pacific Bell in California, Bell South in the south), and a long distance phone company (AT&T), and it became possible to choose a long distance carrier, if you wanted to make long distance calls. The local phone companies were not permitted to provide this service, although AT&T may have been allowed to be a default choice. This unleashed real competition in long distance service, it was now fairly easy to switch, and as easy to dial, and there were several companies ready to go, because they had been offering less usable services already (dial a local number, get a second dial tone and dial the actual destination, etc); prices dropped, quality improved, etc, etc.

In 1996, we got a Telecommunications Act which among other things, required the incumbent local telephone services to lease access to their lines at cost based rates. Under these terms, if there was sufficient space in the central office, a competitive local carrier could install equipment and provide local (and long distance) calling and DSL.

However, the regulator (FCC) said this only applied to telephone service and not to "new" services like phone and internet via cable TV lines.

Additionally, DSL length restrictions meant many customers weren't close enough to the Central Offices to get good service, and phone companies began building out remote terminals to house the equipment closer to the customers. But there's no space in a remote terminal for competitive carrier equipment, so that wasn't necessarily required to be available either.

Finally, courts ruled that it wasn't fair to impose leased access requirements on telephone companies but not cable companies, and the regulator declared the market competitive because consumers could chose from their telephone company, their cable company, internet over power lines (which I don't think every actually happened!), or wireless, so line sharing wasn't important.

An additional wrinkle is that although the leased access prices were regulated, and supposed to be based on cost, incumbent carriers would regularly price retail accounts below the leased access prices, making competition unfair.

There are a few open access networks that were explicitly built out for this, but it's pretty rare, or it comes with big caveats: I can get on my municipal fiber network where I live, but I'd have to pay all the construction costs to get the network extended; if I organize a group, we can split the costs, but interest is low, I'd rather be able to do it, but get partially reimbursed if someone else connects up on the line I extended (within a reasonable time).

TL;DR: we almost had it, but it was a bit broken, and then it was taken away.