I used Uber over 100 times while my crocked knee and foot was not ok to walk or ride on. Luckily my client covered the cost.
My experience was that a lot of the uber drivers were either studying and using uber as a useful part time income or were business owners or part time workers who wanted to top up their income.
Most that I spoke to liked uber because there is no cash to handle, tax is deducted at source thus avoiding tax returns (I wonder how many black cab driver's tax returns are 100% legit?) and their only requirements were a phone, to pass an interview to ascertain your language skills and to have a suitably insured car with appropriate minicab license.
Beats the hell out of spending two to three years doing the knowledge and then spending £40k on a hackney carriage.