In cold areas, every rental unit's parking spot comes with a power outlet so that you can plug in your car's block heater. So it's possible.
I think it's a different sort of effort to wire every parking spot with, say, a 40 amp, 240 volt circuit to enable moderately fast charging.
Mind you, some small part in me is sad at the idea of yet another device around my home that I have to remember to charge each night.
And I would expect that as EVs become more popular, chargers will start being something tenants will ask about. This will in turn put pressure on landlords who want wealthy tenants to wire up their garages for faster charging. We've done the same thing before with heating, washer/driers and internet over the last few decades.
And the point isn't that it already covers 100 million, just that if there's a need (like there is for warming cold engine blocks in winter), it's neither particularly complicated nor expensive to provide this kind of overnight trickle charging.