Been with BT forever.
Last house (rural) after many visits they were going to send out 2 teams of engineers and a cherry picker to replace ageing local pole and cable. Final engineer got it working the day before the pole was to be replaced. We got speeds of around 1.5m download.
Current house (semi rural), engineer spent all day replacing 100m of phone cable. He climbed all the poles between our house and the lane, cut back overgrown trees and got a cherry picker along (the same day) as he wasn’t allowed to climb the final pole as it was a different type. We get 1.3m download.
My experience has been that living where we do it’s only BT who don’t mind throwing resources and money to give us broadband which will take years to make a profit from. Their customer service is what it is but as long as you jump through all their hoops your case eventually gets escalated to an engineer visit. As their helplines are all 0800 who cares if you have to hold a while to get through or call them back every 2 days for a resolution.
I guess if I lived in a town or city where broadband was guaranteed I might look at other providers.