I mean this is the case universally, even if the losses aren't in a specific line item the cost of generating that power has to be covered overall

There's usually an incentive to solve this though because this shrinkage, in retail terms, would be handled at the cost of power generated (without any profit margin) whereas if it was sold to a paying customer it'd have a margin built in. If the Greek utilities are allowed to make a profit on that losses line item, that is insane

If a utility is regulated to a set profit outcome, it will make a profit on stolen electricity just via math.