> In Europe its just kwh.

In the EU, yes. When you go to those dark corners of Europe that never achieved the membership, all bets are off.

In Montenegro and Serbia they charge per minute because the only entity allowed to sell kwh's is the national electricity company (in Serbia it's owned by Russia, so it is heavily legally protected).

In Italy there are enough chargers that charge for both kWh and time connected. kWh for what you use and connected to discourage being connected all the time.

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.

[0] https://www.tanke.io/oeffentliche-ladestationen/

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.