Gettin it how you live.
College takes 4 years for just a bachelors. More years for a master/doctorate. If you spent those 4 years seeking out money making ideas and following through with them you'll come out with more money and real world experience then any of those college graduates. The hard part is finding fresh lucrative ideas and getting the start up cash to invest. But if you actually do it its way more rewarding then college. Thing is most people won't actually do it. They need the structure of school, grades, bosses, etc in order to get motivated. When your self employed you have to be your own motivation which can be hard at times.
At the end of the day you'll always make more money striking out on your own. As long as you follow the systems set plan (school, college, job, retire) your income level will always be capped. Thats why only 8% of people make over 100,000 before taxes. Cuz 8% of people had the vision to be the boss. Everyone else either followed the plan or straight up failed.