Fundamentally, is this a problem with eBay/PayPal or how credit card companies deal with chargebacks (and eBay/PayPal simply having to parrot the same model)?

Fundamentally, is this a problem with eBay/PayPal or how credit card companies deal with chargebacks (and eBay/PayPal simply having to parrot the same model)? As part of a large OTA, I've dealt with credit card chargebacks in the travel industry and it's really not pretty. As soon as a chargeback is received by the bank, you, the merchant, are presumed guilty. It's up to you to prove your "innocence". The buyer can simply claim one of the many frivolous reasons without providing an iota of proof and you'll be stuck with providing reams of paperwork - chargeslip, e-ticket, boarding pass, verification from airline that the passenger boarded the plane, etc. etc.