That’s not really true. Although it is true that how you move up has nothing to do with school, the fact of the matter is is that for companies like Facebook and Google, etc, they are looking at the cream of the crop for graduates every year. The differentiator is what school you go to. It’s the difference between starting say at 100K per year versus $60K a year.
If you’re going to make the argument about college cost savings, everyone should be staying in-state to go to public schools, and private schools shouldn’t even exist.