I don't switch from FB to another social network unless a bunch of my friends do.
As a consumer, it is very easy for me to install Lyft or Curb or $LocalTaxiApp and switch. There is very little brand loyalty.
As a driver is a harder, there is a burden to onboard to a given app service. But I've seen plenty of drivers with simultaneous lyft/uber signs, so I know they are doing it. And driver forums/social-networks are constantly talking about ways to maximize income, so if there is new app that is better many would try it, because they wouldn't need to abandon the older platforms just to try the new one.
Bootstrapping having both demand and supply is the hard problem of the two-sided market to scale. Riders and Drivers might try out an app easily enough, but they'll only stick with it if there is enough capacity to market-match (and some cost benefit over the other app-markets).