If/when open-weight models do catch up (i.e. become the dominant product in demand), Amazon transitions from a middle-man to the supplier with the best economies of scale.

Great business either way. You could even draw an analogy to Linux/OSS & the origins of AWS. They started as basically an infra middle-man for other people’s technology. But as the core tech commoditized, they transitioned into selling their own higher level services at scale—like Bedrock.