I find it hard to believe someone who wanted to work for free on something meaningful would choose to volunteer for DoorDash in preference to a normal charity?
I don't think most of them were in a situation to say "I want to work for free" and then chose DoorDash (per definition a for-profit job) over volunteering for charity (per definition a non-profit job). I could imagine they found the job, it generated some cash flow and only they later realized that the math doesn't work out.
