"Only because gasoline for road use is taxed much more than electricty. At present."
Around 80% of UK pump price is tax. The rest is crude oil, transport and refining costs.
IE: the real price is about 1/5 of what you pay at the pump.
Expect to find that road charges of some sort are rapidly introduced when EVs become the norm.
The UK government is _not_ going to give up £60billion/year in income without a fight