[mabbo]

It could very well be.

But how many of those routers could they make, and how quickly? And for how much? And could they really handle the kind of load that Amazon needed to handle? And how quickly could these bespoke solutions be installed, tested at scale, verified to work? Would the manufacturer provide support if they don't work as expected?

The solution that was done was to split the network into sub-networks with just the few proxy gateways between them that were needed. And it worked- I think it's still working that way. That's not free to do (every service owner had to do some networking work), but it's also perhaps less expensive than switching out all the hardware, overall.

And rest assured, Amazon always chooses the option that maximizes profit in the long run. Other than that stupid phone.