Would love to see source data that Uber is referencing (I know it's not possible, as it's highly guarded secret) - I suspect they cherry pick it a lot. "In the US, 92% of drivers drive less than 40 hours per week, and 45% of drivers drive less than 10 hours per week. [...] We will continue to defend the innovation that makes that kind of choice, flexibility, and independence a reality for over 200,000 drivers in Cali…
A very clever thing they're doing is conflating being an employee with not having flexible hours, as if part time jobs don't exist. Fast food chains don't hire independent contractors and yet lots of people have flexible shifts.
Fast food chain is busy from 12 AM - 2 AM, 5 PM - 7 PM. These shifts may be desirable or undesirable because of the time they occur. To be able to get the "easy" shifts (slow ones) at 10 PM or something, they can make it so that you HAVE to take a part of the other shifts... If you can't, you don't meet their eligibility and you lose your job.
If you are an employee in a shift based business, you definitely give up some rights to having completely flexible work hours.