I think the point is that if battery technology is good enough, it's not the limiting factor. Being able to deliver that much power becomes a bottleneck. At some point the owner of the parking lot will have to upgrade their electrical service, which could be expensive.
I'm not sure how much of an issue that really is, though. Even if all cars are EVs, it's not like every single grocery store customer is going to fully charge their car every time they buy groceries.
I'm not sure how much of an issue that really is, though. Even if all cars are EVs, it's not like every single grocery store customer is going to fully charge their car every time they buy groceries.