If I spend $100 on gas and get reimbursed, I get $100 (tax free), if I don't get reimbursed the US government gives me a $30 discount (assuming a 30% tax bracke

If I spend $100 on gas and get reimbursed, I get $100 (tax free), if I don't get reimbursed the US government gives me a $30 discount (assuming a 30% tax bracket) on my income tax. That $70 difference for the drivers is a lot more than an accounting shift. Uber saves $30 on their corporate income tax but they have to pay out $100 to the driver so are also out money.