Let's assume that a driver is dedicated to rewarding:
Making 90 orders should be almost 2700, and 90 orders should be subsidized 1280, that is, Uber should be subsidized 1280-2700*0.2 = 740, that is, Uber will lose 740, but there should be fewer drivers who don't get rewards and drivers who are caught swiping bills every week, so Uber should still be in a loss state at present. Uber doesn't have to worry about this problem, its valuation has reached 53 billion, and it has enough money to burn.
However, the subsidy for car number one is actually very small, and it should have been profitable long ago.