Indeed the school is important. but can the school guarantee someone to be successful? the answer is no. many people go to college and eventually they only become unemployed. meaning that the school cannot guarantee your success. the school is useful so that someone has a broad mindset, so that someone has a broad association, and so that someone knows good and bad things.
and when you go to school, your teacher invites everything. from religion, mathematics, physics, chemistry, biology, sports, and many others. and your parents demand that you graduate from all of these subjects. and when the results come out, it turns out you get some bad grades. so you don't pass the test.
This means that you don't like some of the subjects so you get bad grades. I'm sure not all your subjects like it. How can someone master all knowledge? of course you will not be able to master it. therefore I say the school does not guarantee someone to be successful.
all you have to do is learn what you like. for example you like business. then you learn about business. don't you learn everything. It will only make you confused, and not focus. and when you have learned what you like, chances are that you will become a successful person.