Selling on eBay only makes sense in bulk, with hundreds or thousands of SKUs. I gave up selling in low volume there long ago; nowadays for phones, tablets, and watches I use Swappa, and for anything else it's Craigslist or local "online garage sale" groups on social media.
The company I left last year sells the bulk of their products on Amazon, and maybe 1/4th of their inventory (same type of products) is listed on eBay. Amazon sales are relatively smooth with much less friction per sale than eBay. It's gotten better since they went with a sales aggregator service, but they still barely break even on eBay as opposed to Amazon and physical storefront sales, when they figure in labor and time costs. When I worked there the sales personnel were able to list five or six items on Amazon in the time it took to list one item on eBay.