I imagine most contract delivery workers have considered this and factor it into their decision making. I don't think these positions are meant to be a perfect improvement across the board to traditional starting wage jobs, but it's up to the employee to make the judgement based on their own risk tolerance.

Like many folks here, I worked full-time minimum wage for years before eventually entering the professional world, and I can say given the choice now, I'd absolutely prefer the make-your-own-hours contract model to obligation of a fixed-hour in-person position. Of course there are drawbacks, like the lack of health coverage (though I'm Canadian so I'm not sure how this would work in the states exactly), but given the option, I'd still choose the former.