Yahoo "owned" the net not that long ago, now they're completely irrelevant. Microsoft "owned" the browser market with Internet Explorer not that long ago, now people cringe when they have to use IE. MySpace was at one time the most visited social media site in the world, now it's merely a quirky bit of internet history.

Google, Facebook, Amazon, etc. do not "own" anything. They are businesses that exist in a fiercely competitive environment in which consumers have zero loyalty and will gladly switch to the next hot thing at the drop of a hat. These businesses are successful because they continually innovate and deliver products that people want. There's no guarantee that any of these companies will still be around in a decade, much less "own" the market they operate in.