I'm fond of Netflix?

Wouldn't need datacentres if we had IP multicast routing. And actually, Netflix doesn't need that anyway: anycast and telco CDNs get most of the advantages, albeit at the cost of only being available to established players. Netflix uses AWS because it's cheaper and easier for them, not because it's technically necessary: if AWS shut down (with enough notice), Netflix would migrate to an alternative system, and nothing much would change.