It’s my understanding that Uber Eats drivers see a particular order and estimated earnings for that order come up on the app. They have the choice to either accept or reject that order. The amount of estimated earnings varies on a number of factors such as how many miles of driving and required shopping time, supply and demand at that particular time, size of order, and tip. In my area, nearby orders are often combined by app. Having a dependence on so many factors makes it difficult to give a specific number, but average is often not much above CA minimum wage. However, under CA prop 22, there is a minimum payment of 120% minimum wage or $19.20 per hour + $0.34 per mile driven.
My experience is drivers will almost immediately accept my orders, so whatever they are paying, drivers in my area seem willing to accept offers for that rate.