There are jobs where you don't need any experience and education anyways. The ones that are typically considered minimum wage jobs, like cleaning or restocking shelves. Employers shouldn't be able to hire teenagers for cheap just because they're younger, especially since a teenager isn't going to be less productive than an adult with those types of jobs.
I'm curious given your view that employers shouldn't be able to hire teens to do low wage jobs what you think about immigration. Is it the same thing, that we shouldn't allow low skill immigrants because they will compete for minimum wage jobs, or do you have a different view there and if so, why?
Otherwise, what experience and education do you expect that a brand new adult entering the job market to have that a teenager will not? An adult who needs (at least) minimum wage to be able to survive, and a week ago was a teenager. Who is going to hire such an adult when they could hire the teenager, with identical experience and education, for cheaper?
Low skill immigrants are still getting minimum wage aren't they? You're arguing that teenagers shouldn't even get that much. Or are you suggesting that low skill immigrants shouldn't get minimum wage either?
One guy I work with has 8 children. Another is married to a partner in a law firm and lives in a home likely worth >$5M. I don’t pay them any different.
If there was no exception to hiring people who are financial dependents you wouldn't be able to hire on such a person for a small rate. You'd either have to overpay, discouraging you from hiring them, or not hire them because you couldn't justify the expense.
Perhaps such labor is uncommon in your profession, but there are many professions where it is common. The kid at the mechanic's who answers phones and gets things for people may not actually be all that valuable compared to a wage high enough for two people to live off of. The job may be really valuable to the kid though giving experience and a bit of money.
In my business, interns are super valuable. We pay $20-25/hr depending on skill.