It is though. They are actively working on increasing their marketshare. That doesn't happen by accident. They have chosen to place the interests of the corporation over the interest of their fellow people. They are fine to do that, because we separated that responsibility. Corporations can only chase for profit, because we have governments, that make the rules, so that chasing profits is in the interests of the people.

Maybe you don't like that, and that is fine for you, although I don't like that you don't like that. Maybe you want a society where might makes right. However a lot of people don't feel that way, hence why we outsourced that world model to the government.

People don't like that their neighbor is stronger than them and takes there stuff, so they pay feudal lords. Then the feudal lords want some security, so they outsource that to elected emperors. After a while the feudal lords misuse their power, so parliaments are invented. Eventually people have enough and demand voting rights. The elected leaders betray the people by sending them to war, so they created multinational institutions, that try to prevent this (EU). They haven't used their power to betray the people enough, so we are still fine with them.

"Wealth comes with obligations" is literally in my country's constitution. You, may don't like that, but I do. I think a lot of other people do as well. It is of course always for discussion how much.

When rephrased like the above, I think what you’re describing is pretty common in history. Many industries and assets have been nationalized when it serves the state’s interests.

IMO the moral justification is that there is no ownership or private property except that which is sanctioned by the state (or someone state-like) applying violence in its defense. In this framing, there’s little moral justification for the state letting private actors accrue outsized power that harms consumers/citizens.