Actually, they are a media company. Their "edge" is in content creation and licencing deals. They might have been first-to-market for mass-scale streaming, but streaming video technology is a commodity, and they know that they will live or die by the desirability of their media catalog.
> Netflix for example, is completely at the mercy of Amazon.
Amazon and Netflix were symbiotic for years, as Netflix was a headline corporate customer, and I'm sure they received preferential pricing. And given the quality of Netflix's engineering team, I would be very surprised if they don't have a plan to migrate by the expiration of their contract if necessary.