What did carnegie believe were the relative advantages and disadvantage is of competition the concentration of wealth and the law of competition

The disadvantages are clear. The employer who employs many is always subject to the strictest market and capital standards. So the wage requirements strain the employer and the workers are strained by undrrpayment. He pretty much blames it
on the capital. Humans lose homogeneity. However he also adds that he owe this law "wonderful material development" and D that it ensures the survival of the fittest in every department so it's best for the human race.

It might be the second one