The UK problem is that that majority of ISPs actually get their connection from one of the main backbone providers and the biggest it BT. Unfortunately BT is responsible for the complete telephone infrastructure. Whilst there is supposed competition most get their services from BT.
it's the same here with most companies renting some of France Telecom network, whether it's for the Internet of mobile phones, but they're progressively building their own separate networks. My ISP is different (cable/fiber optic), they got their own network. So basically anyone who had already access to cable TV years ago can get access now to fiber optic (which means copper inside the buildings is still being used); they got a monopoly on cable so...just the bandwidth varies a lot depending on where you live, between 30 and 100 Mb. I got 30 while others living 10 km away get 3 times that but OK, I won't complain, it's fast.
