A decade or so ago, most people would have said similar things about Microsoft, but I get your point in general and certainly would only trust Bezos to be a tenacious competitor.

I think the big counterbalance now is competition – raising prices on AWS would be a boon for e.g. Azure – but I definitely wouldn't want to bet against abuse if one of Microsoft, Google, Rackspace, etc. dropped out. I'm sure Netflix has pretty good forecasts for how much it'd cost to move operations elsewhere as long as a good option exists.