Even with their big fees the most good deals just show up at ebay, we dont have a similiar platafform working with bitcoin, and if we had we would still have a problem, we would need some escrow service to act between buyer and seller, because the product might be damaged and the buyer will ask for a refund. At the next 10 years i believe they will reduce those fees, otherwise crypto world may get their business.
I don't think that the next 10 years they will reduce fees because of the inflation as well as the cost of living is increasing yearly. Instead of saying that ebay/paypal will have a reduction for the fees they've got, they will probably improve their service and that will be charged to their consumers, including me and you.