My town has on average 1 car per household, but I'd guess like 0.25 off street spots per household. That's a lot of infrastructure on public land.
It's just an electrical outlet. There are dozens of them for every parking spot already, in the house/office/building. Adding an extra electrical outlet isn't hard for a homeowner/lot-owner to do. This isn't going to have to happen overnight. It will happen slowly over two decades.
Regardless though, you're correct that it will take decades, but I think that this is one reason why a CEO wouldn't be all in. If it's going to take 25 years for a large chunk of customers to buy an EV, you still have a lot of cars to sell that are ICE.
It's just a normal plug, maybe with some components related to metering and billing included. Load balancing if you want to be fancy.