To your first point, eBay has started the dark pattern of not really displaying seller reviews. You can still see them if you're looking for them specifically, but the main stars they post at the top is now a review for the item itself, not the seller. I just got burned last week, complete with fake UPS tracking number. When my item didn't arrive, I checked with the seller and the seller no longer existed and the item was removed for ToS violations. To its credit, eBay gave me an immediate refund, but had I realized the seller had been brand new with zero reviews, I would have thought twice.

> Ebay has seller reviews, and I know who the seller actually is.

So does Amazon, when fulfilled by the seller, which many are. They're exactly the same in this regard.

Amazon commingles inventory with the same SKU. You can choose a legit manufacturer, and they get credit for the sale, but you could still receive a counterfeit item that was actually stocked by some scammer. (Later someone may choose to buy from the scammer and get a genuine item by mistake.)