Ebay should directly accept bitcoin payments and then it would be good enough as PP can be charged back but not bitcoins.
I was about to post the same, but then I realized how volatile the Bitcoin is. If Ebay accepts direct payments in the form of Bitcoin or other crypto, then there is a chance of incurring loss, as the exchange rate can wildly fluctuate in a matter of minutes. So it will be better for them to go for Bitcoin-based payment processors, such as Bitpay.