Someone has to build quite a few more power stations though.
Assuming you're talking about swapping a large fraction of the car fleet to EV, not just a few here and there.
That's a substantial increase in total electricity demand. Enough to radically impact the load on the grid.
And if you end up burning natual gas / coal to meet the marginal increase in demand - as would seem fairly likely - then much of the thermal conversion losses you're saving in the higehr efficieny motor just get shifted to the furnace in the power station and transmission/distribution system; so that can erode some of the efficiency benefits.
I guess you could require for every new EV that they also install roftop solar PV and basically buy a spare battery of near same capacity as the car. that might push the up front and periodic replacement cost a bit though - quite nice for the running costs i guess.
Another good alternative is to try to convince people to get together and share their electric motors in things callled trains and do as many trips in those as possible - that's not too popular with most people unless the road congestion is really bad. Something to do with sharing being communism i think,