Nobody really knows who’s Authenticators are better.
IMO the best thing about eBay is you get to see the actual shoe you’re buying (unless the seller is D-bag). Obviously with StockX and Goat you’re buying blind except for used on Goat. It can also be nice that you can see the seller profile and feedback on eBay. Check for red flags or get peace of mind they’re legit. Also seems like eBay can save a dollar or two - sometimes.
The biggest downside with ebay IMO is they use robots, monkeys, and dumbarses for customer support. So if there’s an issue, good luck. You can’t contact the seller, it’s blocked. I heard StockX support is trash but idk myself. Not sure about Foot Locker, I mean Goat
In summary, I hate them all