There's nothing about having a staffing company involved that forces drivers not to pick when they work or how often or where. When you're a contractor, your contracting company cannot enforce those things, however, when you're an employee, you absolutely can have those things -- or not -- at the discretion of your employer subject to the terms of your employment relationship.

All having a staffing agency involved does is force a minimum wage, and an employer-employee relationship. They, the staffing company, take on fares from Uber and disperse them across their drivers. They pool the fares to provide a minimum wage and benefits, and then anything else above that gets distributed to the driver who created the specific revenue as "incentive pay" in exactly the way the parent suggested. Or as profit sharing proportional to work performed.

There's nothing crazy or unprecedented about this.

tl;dr: The company contracting you cannot tell you when and how to work, an employer can -- but does not have to.

A staffing company wants to reduce the amount of unprofitable hours driven. To do that they have to restrict working hours. It's not guaranteed but a highly likely outcome of the set up.

Are you sure? Have you ever worked in a job at the mall that was relegated to telling you to "I dunno, why don't you come in when you're feeling pleasant or comfortable?" Similarly, airlines that schedule flight attendants don't tell them to come in whenever they want. You can fire people who are your employees, yeah? And you can pay people who outperform more.

Zero chance the bulk of the surplus gets distributed to the drivers. I know of a few New York medallion era brokers keeping an eye on the California market, and they aren’t doing it because they plan on passing along profits.

If you force them to a fixed hourly wage, you can't hire that person and still let them work those hours in those places, because you'd be paying them for 40 hours while they're still only working 10. So the now money-losing employee either gets a pink slip or has to work different hours.

Next, you provide incentive payments for drivers proportional to the extra amount they brought in above and beyond the minimum wage for the hours they drove, as a slice of the pool of revenues after subtracting out minimum wages and benefits. Then you stack rank your drivers at the end of each half, and fire the bottom 20%.

I'm not even advocating this approach, I'm just saying there are ways of incentivizing this that are shown to work. This part here isn't rocket science.

This is commonly repeated and there’s nothing inherent an employment forcing fixed hours or less flexibility. It’s false.