Have you used eBay in the last few years? It's awful for sellers and awful for buyers. This is coming from somebody who buys on eBay twice a month on average.
What would make it better? My only complaint as a seller is fees. I have no complaints as a buyer.
The best part is eBay works exactly the same as 10 years ago, as far as I can tell.
I use it more frequently than Amazon for used books and DVDs. It's cheaper and the sellers are often exactly the same.
It’s still way better than Facebook marketplace. At least eBay mostly solved the scam issue. Zuckerberg seems to desire fraud on his platforms.
And yet, it's still the place to go to buy anything secondhand or used. I'd go so far as to say eBay could be nationalized under the Defense Production Act due to the critical role it plays in manufacturing by keeping obsolete manufacturing machines running.
It's not great for sellers either. I was banned during the time period before the Paypal divestment for having the galls to subpoena a nonpaying buyer's records. They take a cut from both sides. Sotheby's takes 10.5% (I think). eBay takes twice that for something comparable in value.