Just to be clear, there's no specific "road tax" in the UK - it was abolished in 1937. Instead general taxation (e.g. income tax) pays for roads.
Your point about places becoming further apart has been made by Cory Doctorow who refers to it as "geometry hates cars".
Edit: found the Cory link - you might find it interesting, but I suspect it's detailing what you already know
https://thewaroncars.org/transcript-episode-79-the-end-of-ub...
While this is _technically_ correct, most powered vehicles on UK roads have to pay Vehicle Excise Duty, which is popularly known as "road tax".
Of course, with the 4th power weight relationship with road damage, ordinary cars are not really causing much damage compared to buses and trucks, so maybe it's better to state that we're subsidising logistics companies.