Its just a cost of business, and if you’re accepting paypal goods and services payments then really thats what you are, hence why its now called that. Any other card payment wouldn’t get any fees back and normally a refund charge too, so it wont have a bearing on business refund policies as thats what were all used to. Right to return etc will still override any question on charges.
Of course the problem is for Joe bloggs selling an old set of forks and wanting goods/services so they don’t get scammed. But again there you could argue you’re paying for protection. if you want to offer a refund paypal still have to cover their costs – i suppose if you’re legitimately not a business then you don’t need to offer a refund unless the goods are faulty/not as described etc in which case more fool you, if the buyer just doesn’t want them then thats their choice, refund less fees.