You make some very good points, i have been thinking broadly the same.
For those who can afford a new BEV or a fairly new used one there’s not much of a problem, however there are many people who can only afford a few thousand pounds for a banger.
Many will sinply not have the money to buy a half decent used BEV, petrol will soon be unafordable nevermind road tax so these people will be forced off the road and onto our inadequate public transport, so those in power can claim they have achieved the emmisons targets.