So talking to drivers, this is my understanding. When Uber started in my country/city a few years ago, drivers could earn X/month if they drove for 8-9 hours a day. Moreover, it was a smooth gradient, so some weeks they could work less and their take home would only go down linearly.
Over the years, the bonus system was implemented. Now, if they drive for 8-9 hours their take home is like half of X/2. Instead they have to drive 12 hours a day and do at least Y rides in the week, to be eligible for roughly a X/2 bonus so their total take home is X.
So, I meet so many drivers who seem super stressed and tired. When asked they say, it is the end of the week for them and they need to complete another 3 rides for the bonus, but they have already been driving for 15 hours, and only have 2 hours to complete the remaining 3 rides.
Its exploitation at its finest.