A monopoly in itself is not illegal, it’s the misuse of monopoly power that is.
Now there’s a million ways Google has been alleged to misuse it’s power, which is why there’s a court battle ongoing.
But even if a company has 100% market share (and the government/company/courts/public agree on how that market share is defined) as long as they don’t abuse their power no antitrust violations have occurred.
A monopoly in itself is not illegal, it’s the misuse of monopoly power that is.
Now there’s a million ways Google has been alleged to misuse it’s power, which is why there’s a court battle ongoing.
But even if a company has 100% market share (and the government/company/courts/public agree on how that market share is defined) as long as they don’t abuse their power no antitrust violations have occurred.
Edit: under US law. Also not a lawyer.