So in my experience, having an electric car in London is super convenient. There's myriad ways to charge it and increasingly good rapid charging options along major routes. But I'm sure that's not everyone's experience in every neighborhood or city. Hopefully things keep improving as rapidly as they have been.
NB: I have seen someone in London string a charging cable up through their non-ground-floor apartment window once, but only once :)
Plus, while what you say is probably feasible for bigger cities, I'm not convinced yet that small to medium sized cities will introduce something similar anytime soon, or is it the case in the UK?
Just out of curiosity: how far apart are the lamp posts in London? How difficult is it to actually get a parking spot by one? Can more than one car in the vicinity of a lamp post charge their car or only one per post?
Or, you use a carshare, and the car is located in a garage/lot where it spends every minute it's not in use plugged into a charger.
EVs aren't a solution to the unsustainability of individual car ownership in high population density areas.
There's no (usable) car sharing services that I'm aware of where I live.