Can you actually buy GPUs now? An advantage of Amazon in the past was that they were actually available there, where they weren’t available to buy in practice.
Over the last decade there was often a major problem in GPU supply. Huge users like Amazon were presumably buying in bulk direct from manufacturers as custom runs so weren’t trying to buy them on the open market like everyone else.
Even other clouds had major problems getting them at some points.
There were lots of GPUs being bought up for crypto mining reasons, but that doesn't seem like it has been as big of a deal in the consumer market recently (at least locally.)
If anything, it generated a lot of cheap secondhand cards for sale in some places.
You can even buy Tesla V100s that power AWS accelerated instances.