> An economic and political system in which a country's trade and industry are controlled by private owners for profit, rather than by the state.
A privately-owned monopoly that ruthlessly crushes all competition is just as capitalistic as a privately-owned competitor in a market with perfect competition. The key concept is private ownership and control, not competition. Competition is is only required if you want the resulting system to have some positive externalities for consumers and society at large.
Actually, I don't think it does:
https://www.lexico.com/en/definition/capitalism:
> An economic and political system in which a country's trade and industry are controlled by private owners for profit, rather than by the state.
A privately-owned monopoly that ruthlessly crushes all competition is just as capitalistic as a privately-owned competitor in a market with perfect competition. The key concept is private ownership and control, not competition. Competition is is only required if you want the resulting system to have some positive externalities for consumers and society at large.