Same with pizza delivery since forever.
As a pizza delivery driver, your pizza shop is your base and you only go out when there's an order that needs to be delivered. My friend used to work at Pizza Hut and he was getting reimbursed for gas (per mile but it was slightly more than his gas mileage so i suppose it covers for wear and tear?).
As far as i know, you're not getting reimbursed for delivering DoorDash and the pickup location could be on the other side of the town.
With pizza delivery, you have to drive to the person's house then back. So you cover the same road twice for a single delivery.
But with DoorDash, theoretically, then could see there's an order from A to B, find a driver near A, have the driver deliver to B, then match that driver up with an order from near B to near A. So the driver could do 2 deliveries in a single out and back trip.
$2000 will get you a pretty decent vehicle and is probably a better investment than a $1000 repair.
I've since realised that cars are very expensive and you should probably not take a job that requires a lot of driving around in your own car if you don't get reimbursed for it.