Say you average $x per year for 3 years, then your startup fails, so you join bigcorp at $y. So at the end of 4 years you have 3x+y.
Your conservative classmate joins a bigcorp and stays there 4 years averaging $z per year. So he now has 4z.
It's a simple exercise to enumerate tuples (x,y,z) where 3x + y > 4z.
Literally in every case I have seen up close and personal, the LHS exceeded the RHS. And I'm not going to argue with math.