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.

I wouldn't be surprised if the majority of Netflix's true overhead were actually DRM and account management, rather than the international distribution of perhaps a petabyte of multimedia data, most of which doesn't change. (https://news.ycombinator.com/item?id=33456782 estimates half that; https://redlib.catsarch.com/r/NoStupidQuestions/comments/6mf... estimates a tenth of that.)

You have no clue what you're talking about while trying to act smug and talking down to someone who knows at least a little bit more than you. Netflix cannot run without massive DCs, whether that be theirs or Amazon's.