About time telecom companies were forced to provide a decent, minimum speed everywhere. BT made around 2.5 Billion profit in 2017 so to say they cannot afford to roll out quality internet in rural areas is just nonsense. Also, other telco's 'rent' BT equipment so that negates the argument of paying for infrastructure for another company to use it. Besides all that, a couple of quid extra a month for all customers would still reap additional profit after any new infrastructure costs.
No, you do not need to dig up roads. I have a local rural service (HeathNet) distributed by what is essentially an upgraded wireless network. The main feed is from 2x T1 fiber lines located about 20 miles away. The feed to my cottage is in excess of 220Gb/s (I saw the connection speed test) though this is capped at the receiver on my cottage at 30Mb/s and costs me £20 per month. Hardware cost I'm told by the provider is very low, so for BT or anyone else to claim costs are prohibitive, is complete nonsense. If a family run, local business can provide a better internet service than BT (and at a profit) at lower costs, I'll never be convinced about the 'prohibitive cost' argument. I should add that I also have a DSL (telephone line because the fiber box is over 1 mile away) connection provided by TalkTalk, which uses BT OpenReach infrastructure and I'm lucky to get 1Mb/s, when it is working.