Airbnb and Uber have nothing, 0.000%, to do with sharing. They have simply built a digital infrastructure for renting out rooms and selling taxi fares. Their success lies in the fact that digital communication systems are significantly lower cost and more flexible than pre-internet ones. They now own that infrastructure 100% and aim to become monopolies.
(Edit: Another good example of a digital infrastructure company is Amazon. That's what they are, not a retailer or anything else.)
(Edit: Another good example of a digital infrastructure company is Amazon. That's what they are, not a retailer or anything else.)