I don’t disagree with that, but that doesn’t change the fact that overstay fees currently do exist on some EV chargers, e.g. Tesla chargers. I’d also not like to regress and have to wait that extra 5 minutes if possible since I don’t have to currently do that - plug in, leave the car and by the time I’m finished eating (20 mins) it’s ready.

It is also expected that you move your car immediately after filling (then paying) an ICE, in my country at least. Sometimes this can mean people waiting a few extra minutes for them to move their car while they go in to pay.

I think it's a chicken-and-egg problem: chargers have overstay fees because charging times can be very long and it's expected that people will plug in and then leave to do something else. If charging times were extremely short (five minutes), then this expectation would vanish and people would be expected to stay with the car while its charging and then vacate as soon as possible, and then there would be no need for overstay fees.