Great for the customer? Not so much these days. I would happily trade my 2-day shipping for a no-counterfeit/safety guarantee.
Would I prefer a genuine article assurance? In general, yes. Would I prefer that over a wide selection of products and range of delivery services? Probably not.
For anything outside of books/music/movies/video games I nowadays mostly use other retailers, and generally those that specialise in that kind of item.
I recently bought some shelves from Amazon that aren't as described and getting a return and refund has turned into a complete shitshow. Totally fed up of Amazon.