I think electric cars centralise the problem of air pollution, which in turn makes solving the problem from a centralized place more efficient and can be improved as technology improves.
It's like when centuries ago, urban places didn't have sewers and just let the excrement flow down the open gutters on the street (we are here with combustion engines). In time, sewers were built, but the untreated sewage would flow in to rivers & oceans (similar to as if electric cars became the norm now). In time, sewage treatment plants were also built (power generation shifts to fossil fuel-free).
Same way as we now look at open sewers in disgust, I'd say down the future we'll probably look at combustion engines in disgust and say "how the heck did people live like that?"
It's the same with kilowatt-hours. I don't care where it came from as long as it's 1) available and 2) within spec.