The rapid growth of monopoly at the beginning of the XX century. called a necessary evil. Why?

At the beginning of the 20th century, large associations of firms began to emerge in many countries for the production of any types of products or an entire market area. They were formed due to the fact that the rapid industrialization brought to the fore some entrepreneurs who skillfully used their abilities. Thanks to the open market and the colonies, the turnover of their production increased, and at the same time, the capital increased. This allowed one or more manufacturers to capture a certain sector of the market.