If the "capital" in capitalism is referring to Money (capital) that is created out of thin air then yes this is how it works, and you are being naive, thinking the system is creating wealth.

But if it is the right to pool capital in a free market you are referring to then No, it is not meant to have a central controlling oligopoly.  

The Cantillon Effect is a 17th century principal that explains how wealth is extracted from the last spenders of money (the pour) and transferred to the creators of money (the "oligarchs") and how the benefits trickle up relative to your relation to the top,  this principle alone explains how the system is failing humanity globally.  

The benefits enjoyed today are enjoined as a result of human ingenuity and the little bit of the free market that still exists, despite the system we have in place today.