Amazon has been trying to play a parallel game for a while - from one side, they are a brand name store, with their own brands (Amazon Basics), they own loyalty club (Prime), and so on - they even own physical stores and a grocery chain now. On the other hand, they pretend to be a neutral marketplace that has no responsibility for any goods that are sold there and just renting out the space to independent sellers. It is a smart game, as they can resell all the reputational benefits of the established store brand to the tiny sellers who would never enjoy the same reputation, without actually spending the time to vet the suppliers and take responsibility for the goods being sold, as the brand name store would have to. However, looks like the courts are not buying this game. Which makes sense because Amazon not only does not separate the marketplace from the brand name store - they actually make as much effort as possible to mix both up, making distinguishing between goods sold by Amazon and goods for which Amazon bears zero responsibility quite hard to distinguish.
I’ve not experienced the neural marketplace element myself. They still have the A-to-Z guarantee and still have the best return and customer support policies in the game. I spend 10s off thousands of dollars a year and return anything I don’t like. Never had an issue with feeling like they had my back.