This is the problem. They eliminated so many rivals that capitalist competition went through a quantitative growth as a social process and turned into a new quality, monopoly. The pursuit of capitalist competition ultimately results in the destruction of some of the rivals and the establishment of a monopoly. It is a sociological process, the result of the driving forces of capitalist competition and its inevitable tendency toward conversion into capitalist monopoly. Monopoly does not abolish competition.
Capitalist competition continues on a higher plane and exists side by side with capitalist monopoly.
This is the problem. The productive forces engendered by the capitalist mode of production have grown so large, for instance in auto and in such high-tech fields as IBM, that they have outgrown the confines of private property. The answer, according to these experts, is to break them up, downsize them. For instance, IBM's method is to break up its organization into 13 competing units. This is a reactionary process because its sole purpose is to downsize in the interest of profit.