https://www.ftc.gov/tips-advice/competition-guidance/guide-antitrust-laws/antitrust-laws

Microsoft has been hammered for this over and over, and even Europe has an anti-trust law that Microsoft has violated.

Apple seems to be following the same pattern. With hundreds of millions in cash on their balance sheet, they seem to believe they can afford to defend against antitrust litigation, i.e. they will win some, and lose some, so losing becomes a 'cost of doing business.' That seems to be Microsoft's attitude (my son has worked there for years).

The 'restraint of trade' laws are complex, which can be confirmed by doing a 'restraint of trade' query on www.scholar.google.com.

Many states allow private citizens to file state anti-trust actions, with treble damages.

Companies with huge market presence and capital are not completely free to engage in predatory pricing or other actions using market power to destroy or eliminate competition. Congress authorizes treble damages in certain cases, showing how strong the public policy is against monopolistic conduct by powerful firms.