The other E-Niro reached 100% and ten minutes later the owner appeared looking like he had just come from a gym session. So people don't seem very prompt in freeing up chargers as soon as they are done.
I noticed something in a thread along this line and there's a situation where you'll end up like the Gym person
you plug in, car starts charging --- you reckon it'll be x minutes to get to the level you want.
You then head off, coming back at that time.
Meanwhile something's caused your car to actually charge faster and it finishes therefore before you're expecting.
You then come back to a car that finished 15 mins ago vs 3-5mins
(This assumes you don't see an app message from your car saying it's finished, but you could be finishing that 10km rowing session and about to hit the shower )
Or, you're still in the supermarket having to unload the trolley and pay
Someone turns up 10mins before you come out, and they see a car not charging and no one around for at least 10mins.