Uber is losing money and is frequently accused of undervaluing the deprecation and maintenance of the drivers' vehicles.
If Google was to enter a market at a loss in an effort to use its market dominance in Android to drive out a competitor that would potentially be something that would be considered anticompetitive and US regulators would likely be interested in it.
I don't believe that Google can compete with Uber losing money as it is nor that Google has an appetite for purchasing the necessary vehicles and maintaining them outside of a few test cities for a technology demo. Having driverless taxis also means that they would need to do a better job with end user support (compare the urgency of "help, I'm locked out of my email" and their current resolution time to "help, I'm locked in a car and can't get out!").
If Google was to enter a market at a loss in an effort to use its market dominance in Android to drive out a competitor that would potentially be something that would be considered anticompetitive and US regulators would likely be interested in it.
I don't believe that Google can compete with Uber losing money as it is nor that Google has an appetite for purchasing the necessary vehicles and maintaining them outside of a few test cities for a technology demo. Having driverless taxis also means that they would need to do a better job with end user support (compare the urgency of "help, I'm locked out of my email" and their current resolution time to "help, I'm locked in a car and can't get out!").