Yes, they depend on AWS for compute and Amazon also owns a big chunk of Anthropic (it used to be close to 30%, probably less now with the recent raises). I think it's a good partnership since for the most part they focus on different things and I don't see Anthropic going after AWS - they are an AI company first and foremost. Amazon has their own AI stuff for enterprise but no one uses it so I don't think they take it seriously. They know they cannot compete here.

I think that OpenAI and Microsoft is a more challenging partnership with much more overlap.