I have a little sympathy for BT: in the early/middle twentieth century when the infrastructure was being built and the lines being laid they weren't exactly weighing up the pros and cons of G.Fast vs. FTTP, were they?
That said, they do need to improve on things for those with truly poor speeds. I don't know if a government subsidy is the answer, but a good connection does at least need to available to those who want/need it. Otherwise rural communities will suffer, and we should be reversing the influx of people into cities in order to take the heat out of the housing market and ensure food supplies (says he, a city dweller).