On a kw you only pay 5% VAT, but on fuel you pay duty and then VAT which is one of the reasons why fuel is so expensive. The government needs that money to fund other areas like the NHS.
Take away that income from motorists is a loss of billions of pounds and it will need to be replaced by something else which could generate the lost amount and to do that could be through increased VAT, higher PAYE or maybe owners of EVs will need to pay VED and VAT on kw is increased from 55 to 20% all in the name of going green before we are ready.
Make hay whilst the sun shines, and as long as there are tax benefits to running an EV then so be it. How many of us jumped on the diesel 'train' when it was cheaper?
But I'm under no illusion that taxing (whether on fuel, VED or miles driven) is presently advantageous to EV users. But that is not the only reason many people have chosen to go EV. I am certaintaxing will change as the number of EV's on the roads increases.
Many users have considered other important factors, such as the inherent inefficiencies of ICE vehicles and their resultant waste products they continually release. (70 to 80% of the energy in petrol is released as waste heat) Pollution rises every time the engine is run.
The reserves of fossil fuel are depleted never to be replaced with every gallon you use.
EV's are not perfect but they use less energy and produce less pollution in a cradle to grave analysis.
There are presently obstacles to the uptake of EV's for some people, There are too few EV's with decent towing capabilities, and those that can tow still face difficulties with doing longer distances, with inadequate recharging facilities across the country.
This is still early days for EV's, things are continually improving but it will take time for both the infrastructure and the vehicle capabilities to settle out and become as easier. It may never be as easy as it presently is for ICE vehicles.