I don't see anywhere that says the item was shipped and sold by Amazon.com. If it was, then I can see how Amazon.com bears responsibility, but if not then it seems more like an issue with a third-party seller.
Edit: I am describing the process as it is now. I am not saying that it should be this way.
I am simply stating facts as to how the website operates today. Right now, it's possible to order an item on the Amazon.com website that does not come from Amazon.com at all. It can be "shipped and sold" by a complete third party. Most items are shipped by Amazon, but it's not difficult to find items that are just listed on Amazon but the entire sale/shipping process is done by the third party.
The parent comment:
> If you buy on the Amazon.com website it’s on Amazon to deliver your order and provide a good shipping experience.
is simply false, because that's not how Amazon operates today. It is literally wrong because it does not apply to all items on Amazon. That statement is only true if something is fulfilled by Amazon, which includes items "Shipped and sold by Amazon.com" and "Sold by <some_third_party>, fulfilled by Amazon". Fulfilled by Amazon means it's located at one of its many warehouses and Amazon ships it in their Amazon boxes.
If I misinterpreted the comment, then my mistake.
I state what I as a consumer expect when shopping.
You state what is actually happening today.
I think we both agree with both points.