But, at minimum, that university student would need room and board ---plus income to service debt--- to work with you. Not all people have trivial access to that even small income ---particularly if their family does not live in the metropolitan area.
This doesn't mean that unpaid internships shouldn't exist if they otherwise couldn't exist as paid positions, but it does mean that some empathy and social awareness to offer even a couple hundred dollars a week, plus lunch, would help many young people "find something that pays them back in ways that will help them."
I agree that exploitation is wrong, but the key is to find something that pays you back in ways that will help you, and money isn't always the best way to get paid.