1.Uber recently started to offer it's uberxl suv service, which carries upto 6 passengers and in sf costs $5 base fare + the lowest of ($0.45/minute or $2.15/mile)[1].
2.Given enough demand, uber can offer a highly efficient personalized route service, which builds optimal routes needed to transport 6 people. Let's assume such routes can be only 25% longer than normal routes , on average[2].
Combine both of those, we can replace 6X30 minutes car trips , with a single 37.5 minute suv trip, which will be charged $21.87 for 6 passengers, or $3.64 per person.
If we wanted to have a similar trip in public transportation, it would probably take around 1.5-2 hours , but might cost $2.
And if we compare this to a normal car trip, the uber experience could be much better - you could watch a tv episode on your tablet after a long work day and unwind, instead of the stress of fighting traffic. And it's priced pretty closed to the cost of personal transportation.
And the secondary effects from shifting so much traffic to highly efficient forms would greatly decrease traffic jams and further increase speed.
TL;DR - with it's new offering uber is evolving to be a much better, new mode of public transportation, both cost effective and a great experience.
[1]https://www.uber.com/cities/san-francisco
[2]research of "demand responsive transportation" talks about similar efficiencies.