Perfectly Doable.
Completely achievable.
But.
And I say this as somebody who has voted for Boris to be our next PM: I don't see it happening.
BT/OR have done all this all wrong is the issue. Years ago they should have been forcing new builds to be connected by fibre, would have meant hundreds of thousands of homes would have this status. Simple to achieve, doesn't really cost any more money and it'd deal with the first issue - stopping new stuff being copper.
As for installing fibre for everybody else - enough money directed at the right places could get it done. BT/OR for many reasons not least the incompetence shown above is not where that money should be going. They've already had enough money from government to do this and they've simply pocketed it.