Are you asking if every user account is vetted by eBay to confirm that the user is not a scammer, then the answer is "no".
That is not possible.
eBay cannot know in advance what any user intends to do in the future.
Even if eBay had an elaborate way to verify each account, a verified account can still be hijacked by a scammer.
As a buyer, you can avoid a lot of headaches by choosing to purchase only from established sellers that have recent and past positive feedback as a seller for selling items in the same category that you intend to buy. If someone is selling a dozen apple watches, but has no feedback, or only has feedback as a buyer, or only has feedback for selling dress patterns or fishing lures (actual examples I have seen), perhaps wait until they have a track record of positive feedback for selling electronics before you buy from them.
You might miss out on a good deal from a new seller once in a while, and nothing can guarantee that you won't still run into a scammer anyway, but you can avoid a lot of potential problems by choosing to do business with established sellers. Anyone can put together a listing that looks nice -- it is not hard at all to simply copy an existing listing -- but it is much harder to create a history of consistent sales and positive feedback.
If despite your best efforts you do find yourself involved in a transaction with a scammer, eBay has a very good Money Back Guarantee for buyers.
