Letting BT's monopoly steal Virgin's fibre-only customers sounds a great plan!
And then, obviously, what they'll do is sink millions into cabling up a couple of streets that weren't served by either company anyway, just to give people faster speeds at prices that they won't recoup the money from in decades (*).
I think you forget that, apart from new builds that pay for it, the only "cabled" areas in the country were put in by a company that went bankrupt and was bought out by Virgin for a pittance. Everything else is BT / Openreach over cables that have been there for 50 years and/or you have to pay quite a lot to install a new line.
And the rest of the "fibre", even on BT, is not really fibre at all. It's VDSL or DOCSIS 3 with a fibre backend. Unless you have a leased line and paid through the nose to install it, you're not getting fibre anyway (I know - I've bought three of them for workplaces, they aren't cheap but they are real fibre).
(* Do the maths - a leased line install to a cabinet costs on the region of £10k for the install alone.
Connecting that cab to the nearest cab/exchange costs the same because it's all wayleave and digging pipes, not the actual thing you lay inside them.
That cabinet will happily serve the street, if you dig the entire streeet up or run phone lines to every house, costing a lot more than £10k.
And you want to pay, what, even £50 a month? How much of that goes to the people who put in the infrastructure rather than the ISP? Less than a quarter? That's going to take them something like 2000-5000 monthly payments alone just to get their install money back, not counting ongoing costs and actually providing the service to you. How many houses in your street? 50? That means either every house for 10 years, guaranteed, or most of the houses for, say, 20 years. JUST TO RECOUP INSTALL COSTS.
There's a reason nobody wants to pay to connect up people, especially in rural areas where you run 10s of km of cable to service a handful of people. It just doesn't scale without massive subsidies)