I don't think so at least not in the short term. Demand in major metros is much higher than supply. Google will never be able to expand fast enough, in terms of getting approvals from cities, getting the tech right to be able to handle cities, and just the amount of cars on the street. We are probably looking at awhile before it is an actual threat to these other services. Who knows what will happen in that time.

This actually seems to me like a much easier problem to solve than scaling a two-sided marketplace in a lot of places. This is purely a capital + regulation problem and Google has a lot of capital and regulation will catch up as soon as first cities show promise.

If driverless taxis are cheaper - which is likely in the "fully operating in major metros" scenario, then the answer is obviously yes.