I don't think people realize that when they buy something on eBay, they're not buying FROM eBay. They're buying (usually) from an individual or a small home-based business.
When they make a purchase, eBay charges those sellers a fee that is not refunded even if the buyer changes his/her mind or otherwise refuses to pay. (At least that was the case the last time I sold something on eBay - must be eight or nine years ago, now.)
I feel for eBay sellers, these days - everything is slanted so hard toward the buyer while the seller has very little protection.