eBay has long abused it’s customers (sellers) and currently they are engaged in dark patterns to get sellers on the treadmill. If you don’t consistently list items, your other items won’t sell. If you don’t use promotions, it won’t sell.

They rolled out an automatic suggested promotions rate. So eBay will automatically increase your promotion percentage. They also implemented a policy that if a user clicks on any of your promoted listings and then buys any of your items within 30 days then the promotion fee applies to that sale.

Then there’s fb marketplace which hasn’t been showing items to buyers at all for a long time. Search is completely broken.

Then craigslist is just dead.

There’s a bunch of other niche marketplaces like Etsy, discogs, Mercari, Poshmark, but there’s major issues with those as well.

What I’d really like to do is make a website for “math” trades like bgg does. Except you would simply list anything like you would on eBay and then select things you would like in return.