The poor and elderly have some finite amount of money that they have allocated to spend on public transportation, right? Perhaps it's a bit ideal, but Uber has

The poor and elderly have some finite amount of money that they have allocated to spend on public transportation, right? Perhaps it's a bit ideal, but Uber has already successfully penetrated a new customer stratification with Uber Cab...what's to stop it from doing so again -- whether it be via a more cost-effective Uber Cab, an "Uber Rickshaw" service (mostly kidding), or even a government subsidy (an amount to be added to municipal welfare budget, yet still far smaller than the inefficiency cost of a municipal taxi system) to service poorer customers at an affordable price?