I did some napkin math with a friend of mine over coffee and we concluded that just by being brough into existence and to the showroom floor a BMW i3 is equivalent from a pollution point of view to my diesel Ford having done 200.000 miles (I'm nowhere near that).
But people buy electric vehicles in droves since they're government subsidized and what not - albeit this is another bait and switch, it's not forever and charging isn't free either, plus quality overall is quite lacking, not to mention the OTA updates and potential data mining coming from these cars being oversized smartphones with wheels.
I dread the moment governments will up and force everybody to give up their old but reliable and not really hardcore polluting cars - a petrol/diesel vehicle doesn't do anything when it's off even if it's been like that for 20-30 years, an electric car may require to be always plugged in, trickle charging to keep the battery fed so in the winter you don't go to your garage and find out your range is actually 1/2 of what was expected. Not to mention nobody actually knows how long electric vehicles really last, whilst it's not uncommon for people having had the same ICE car for 30+ years.