The Rockefellers and Vanderbilts of yester-century would be red with envy at the size and power of today's tech companies.
Same will happen to Bezos, and he'll be the largest share holder of whatever pieces there are.
Google has 90% of the search market because they have the best product. This is the same reason Amazon is doing well – people just love what they're offering. It's not that you need oil and Amazon is the only player in town – it's that Amazon and Google offer the best gas station experience by a large margin.
That's the problem though. No one in the modern age has traditionally won against these companies, they just get happily bought. It's very arbitrary and sure, it's not breaking any laws, but it's also doing absolutely nothing for promoting a healthy industry. Is this the best "free" market we can muster?