No need to go further than dead center EU to see chargers where the cost has a time component, and an energy component, and even a (small) one time fee. Sometimes the charger is inside a paid parking, there that comes on top. These aren't shady operators either either, just the way they saw fit to prevent abuse and make more money.
Some have reasonable limits to prevent abuse [0], others just charge the customer as much as they can get away with.
Is abuse here just parking in the charger and leaving for a few hours, assumingly skipping any parking fee if you're only paying for kWh?
Abuse means leaving your car parked while it is not actively charging.
Fine to leave for a few hours if your car needs a few hours to charge fully.
Not fine to leave for a few hours if your car was 15 minutes from full.