AS al LL in Uk to be phased out I think Ofcom should mandate number porting and as deadline gets closer and many more peopel impacted i suspect they will.
The whole thing is abit of a scam because you still keep a physical network connection to some sort of switch its just an optical pair not a copper pair. They both carry your internet its just the optical one is faster/ it seems almost everyone now uses their mobile as primary means of voice connection but another access pathway to the internet is always going to be useful as back up for people who need 24/7 connectivity (or think they do) .
Also worth remembering that old fashioned copper pair landines keep working even if power goes to your property and that might eb a reason to hang on as long as possible until BT get desperate for you to move rather than youasking them now to move you.