I would push back on that thought a bit. Consider that in our existing history are door to door sales people who would use their own car to sell goods on a commission basis, the canonical example of that is the "Fuller Brush Salesperson".

Also, assuming these people file tax returns, if they are independent contractors then they are writing off their car mileage at 55 cents a mile against any income they make. Hard to know for sure without talking to actual drivers though.