I've been using it to buy car parts and it is SO MUCH better than dealing with junkyards (LKQ/Car-Parts websites suck!) and everything that I've got so far including parts from Latvia and Germany have been genuine.
eBay too is full of knock-off trash from China but you can easily tell those apart from a real listing most of the time with reviews being unique per listing/seller. And eBay allows for local pickups too!
Small delights like that are worth serious money.
I love sites that have such a structured categorization of their items. McMaster-Carr is the gold standard IMO, and RockAuto is pretty close.
I've had over 200 amazon orders last year, didn't have a problem with a single one of them. Few times I wanted to return something they either sent a courier to collect it from me directly, or just refunded me anyway. And few times I ordered from somewhere else(urrghhh.....Currys) the customer service was absolutely abysmal. I'm just not brave enough to order from anyone but Amazon nowadays*.
*here in the UK, understand the American Amazon is far worse for <reasons>
I now buy a bunch of stuff from AliExpress because at least they don't even try to pretend that (most of) their products are crap. When I want something cheap and don't care about waiting a month, I go there to get it directly from the source.