i.e. they would be wildly popular if they just didn't have any competition?
Why would that make them wildly profitable? You have to find margins better than a taxi company somewhere and not just assume they exist because it's an app.
(I keep making this same post for some reason.)
...and outlast the degradation of their own service. In my admittedly limited experience here in Seattle, the quality of cars and drivers has been going down.