Kids need chores, responsibilities, struggles etc. Coddling kids until they are 18 and then throwing them into the world with 0 life experience is just setting them up for failure. I had a paper route for a couple years when I was 12 and got a job at McDonalds when I was 14.
A lot of this can be learned in extracurricular sports as well, but that's obviously not for everyone. Two a day football practices in summer were harder than any job I've ever had but no one says sports are bad for kids. I don't really see the difference, plus, you don't get paid for sports.
Of course I'm not suggesting kids should be working in the coal mines, but I don't see anything wrong with summer or weekend jobs, working on the family farm, etc. It's good for them and a part of learning how to be an independent adult. Kids shouldn't be infantalized and sheltered through college.