I agree that Uber is trying to replace private car ownership, and I expect ride-sharing services like Uber/Lyft to succeed at this. But given those assumptions, is there any reason to expect them to be massively profitable? The current market seems to involve Uber & Lyft (& other competitors in different locations) competing on price, do you expect that to stop?
Presumably the (publicly) unacknowledged plan is to severely wound private car ownership and then collude with Lyft to fix prices, similar to how it worked with Didi in China [0].
There will likely be some regulatory capture on the side to discourage other competitors.