It's kind of accurate but incomplete. What you're missing is that Amazon does "commingling" in which all sellers of item X (including Amazon itself) submit inventory to Amazon and all of that inventory of supposedly identical items is put together into one big pool. If someone manages to submit counterfeit items, they have successfully contaminated the pool so some seller's customer is going to get counterfeit goods by it probably won't be a customer of the counterfeiter.

That's not actually relevant for this case, however. In this case it sounds like the item in question was not fulfilled by Amazon but was directly shipped by a seller who is no longer active and cannot be reached using whatever contact information Amazon has.

I'm actually kind of surprised by this ruling because it seems like it is requiring Amazon to maintain current contact information for former sellers for some indeterminate amount of time. I guess the closest thing that I'm thinking of in terms of another business working like this is dropshipping where you sell items without maintaining an inventory but instead have the order shipped directly from a manufacturer or wholesaler to your customer. That's actually fairly common with a lot of computer equipment, where you'll see on a website a mention of "ships directly from manufacturer"

I have found that “shipped and sold by amazon” also involves a very high proportion of defective or counterfeit items.

Even with books, there are many copyright-violating counterfeits, alongside many “printed on demand” copies at horrible quality (but not advertised as such) under some kind of shady deal Amazon forced down publishers’ throats.

Unfortunately Amazon has driven many alternative vendors out of the market, so it’s sometimes hard to find things elsewhere online.

I hear this complaint about quality a lot online. But I've been buying for ten years, hundreds of orders. And not once have I had a complaint. The closest I got was a broken Amazon branded space heater but they recalled all of them last week so that feels like an anomaly. So I'm not really sure what to think.

I've definitely noticed a huge drop in quality over the years. Depending upon what you order it's safer to go through AliExpress. I wouldn't buy anything that I value my life or my data for from Amazon.

That is correct.