3 years of unskilled labor will leave a lot with just enough to support themselves while the cost of education managed to go up in those 3 years more than inflation. Meanwhile you missed out on years of good earnings at your chosen profession.

Working your way through school has become somewhat laughable. Your advice would leave the majority of people much poorer for following it.

If you have the time to work enough to pay for 3 years of college in high school and still perform well in the school itself and jump through all the hoops required to get into that prestigious school you always wanted with a plethora of extracurriculars you aren't learning jack in high school anyway and are probably doing severe harm to yourself working so many hours of the day.

Education in general is messed up, mostly because years 5-18 are almost exclusively a black hole of nothing for most people where you go to learn to read, write, and do arithmetic. Which most people will do by age 8. Then there's a decade of Shakespeare, algebra, and dissecting frogs which plenty of people use in their daily lives and that plenty of employers eagerly need more of in the workforce.