there are other aspects to look at, its any anticompetitive behavior, or action that reduces competition.
Exclusive or privileged contracts regarding supply could be the lowest hanging fruit here.
Has nothing to do with the market simply choosing Nvidia if that's the criteria. The antitrust violation wouldn't look at that at all.
but I agree in that it makes it hard to do normal business. smaller businesses do all these anticompetitive things and its the most rational thing to do. when does it flip to being sanctionable? when does it move away from "hey you didn't maximize shareholder value so you're the problem and a judge will agree" to "hey, now you maximized shareholder value and the government thinks you're the problem and a judge will agree"