Sure when all cars are BEVs they’ll be taxed. This has always been a moving feast. But they haven’t applied these tax changes retrospectively.These folk" who are only considering due to cost savings are in for a shock when the government finally apply taxes of sorts to EVs to make up for the lost fuel duty and emissions tax income, which I suspect will start in a few years on a gradual basis.
Eg the Passat GTE Advance PHEV is £0 VED if it is a 2016 or earlier. For 2017 and newer models the tax is £450.
At some point the least efficient BEVs will pay VED. But that won’t apply to existing BEVs.