In my buildings parking garage there are 150 cars, where probably a good 30-40% of cars are BEVs. We're pulling a maximum of 32kW, or 400V/80A. I have yet to find my car not fully charged in the morning. It's a load balanced system, so usually I get full effect of 11kW when charging.
We have troubles generating enough power to not force blackouts in EU and we talk about introducing hundreds of millions of EVs / to every household.
Currently it all works only because they are a novelity.
EVs are certainly not only a novelty in the EU right now.
But yeah, I wouldn’t count on short grocery store stops to charge my car.
But more to the point, how many people have a regular commute, only have street parking at home, and ALSO couldn't be expected to have their employer provide charging at work? Are they doing on-street parking at work as well?
I know a lot of folks in the city who own a car but use it for errands and trips but not commuting. They're the people best served by slower charging at grocery stores, movie theaters, etc. 20 miles isn't a lot but if you're topping up every-time you use the car anyways it adds up or at the least means you only need to use the fast charger once every few months at the most.
The need will become obvious to them once market share approaches 20%.