If you look at the Uber 2019 annual report, page 64, you can see that revenue was $14.1B, cost of revenue was $7.1B, and sales and marketing was $4.6B.

$14.1B - $7.1B - $4.6B = $2.4B

Driver bonuses fall under cost of revenue, and user promotions fall under sales and marketing. It’s only after subtracting other overhead that the company becomes unprofitable.

Other overhead includes operations and support, research and development, and general administrative. If you read the descriptions of these categories it becomes apparent that they are going to need to lay people off if they cut spending there. Sales and marketing also includes a lot of headcount.

All the above math includes both rides and eats. There are other numbers in the annual report that show that rides is making more money overall while other areas are losing more.