Kerbside charging points are already becoming common in many cities, although a lot more are going to be needed. Look to cities like Oslo or Amsterdam for examples of best practice here.

Some boroughs of London are quite well covered, with charging points every 1-2 blocks or so (Westminster), where as other parts are pretty useless (Camden). Because the charge point spots are reserved for EVs only, and can only be used while charging, you can usually find an available one pretty easily.

There's talk of designing charge points that can easily be attached to existing street light poles, so in terms of infrastructure the cost to implement charging points on every street should not be unreasonable, once the demand is there.

I see Teslas and BMW i3's parked on the street near me regularly in London with no obvious access to a nearby charging point, so it's certainly possible to use an EV this way at the moment - if not entirely as convenient as having your own charge point. If you're only driving around the city then you probably don't actually need to charge all that often (maybe once a week or so), and for long-distance trips you can stop at a fast charger or supercharger.