Drivers earn about $9.21 which is less than minimum wage in most cities. SF has a minimum wage of $15.59: https://www.epi.org/publication/uber-and-the-labor-market-ub...
Pretty sure most drivers wouldn't be driving for $9.21 if a job at the local ice cream parlor could get them almost double on the spot. Yet you still see folks driving 30 hrs per week for years.
This isn't as easy as it sounds. Much of their income will go towards paying vehicle maintenance costs, and those are not obvious from the start. Your accounting can show you making decent wages for six months and then suddenly you need new tires and recalculating your wage will show you aren't making a ton of money. At which point many of them do quit and work somewhere else.