They do a few e.g. Edinburgh-Stansted.
So there are, I stand corrected. 3 a day. Enough to not quite fill one 9 car Azuma each way.
If we cut the subsidy by x% this will be the impact (lines close, reduce services, whatever) but we could then raise personal income tax allowances by y". I have no idea what the impact of the full ~50% subsidy is or how that would reflect into say personal tax allowances, but someone must have the numbers, and to be honest that is what the choice comes down to.
Well, current subsidy for the operational railway (excluding railway upgrades) is in the region of £12bn. I don’t know what it means in personal allowances or income tax due to the way banding works, but it is broadly equivalent to a quarter of all NI payments by employees, or abolishing stamp duty land tax, or abolishing all alcohol duties, or (relevant to transport) halving fuel duties.
As you say, political choices.