Amazon, not uniquely, has a business model based around devolving blame and recourse in a way that insulates them from the normal downside risk a business would have. I don't know if this is a consequence of how risk averse the world has become, but I believe it's a source of competitive advantage.
You call amazon about a problem, the only feedback they ask for is about the call center agent, who almost certainly has the least agency or autonomy of anyone in the process but is subject to all the blame. Uber is the same, any problem you have or recourse you want is directed at the driver or restaurant, when both are basically cogs in a machine. But it could never be the company's fault.
Here it's the same thing. It was the "delivery service partner" that was the problem. I'd believe that legally this could be true, but the root cause is still amazon offloading responsibility for any downside onto the "delivery service partner".
I don't know what the answer is, but I think there is some gaming of the system going on where these companies have found a way to offload risk that is not really fair.