[treyfitty]

I think you're misinterpreting what OP is inquiring.

Amazon is the company. The company offers AWS and Amazon Prime Video (I am assuming you mean Amazon Prime Video rather than the e-commerce side of the business). Ergo, providing AWS enriches Amazon. Assuming funding within the company is fungible, Netflix is indirectly helping Amazon Prime Video.

OPs question is: Let's assume Netflix takes this as the antecedent- why do they still choose to indirectly enrich Amazon Prime Video, their competitor?