The problem with the Amazon vs eBay argument I’ve heard in the past is that Amazon blurs the line between when you’re buying from Amazon and buying from a third party. And if Amazon is still commingling items they absolutely should be responsible because at a certain point it doesn’t matter who the seller is.
Seller rating on Amazon are also useless. At least eBay you can see what it is you’re buying (for the most part) and get a seller eating that’s at least somewhat useful.
I really hope this forces Amazon to start vetting sellers more, they’ve simply been run over by aliexpress “drop shippers”.