Also, I’ve observed a rhetorical trend among the “anti-bigness” crowd towards defining “monopoly” down:

“You may think a monopoly is an overwhelmingly dominant position as a supplier of a good or service, but that’s just naive popular economics! Acshually, according to the latest economic theories (by economists who share our politics), a monopoly is any firm that is big enough to have market power—like pricing power—to do things that can harm a competitor unfairly.”

Us dummies will keep calling that competition.

McDonald's is the exclusive supplier of Big Macs and McNuggets. They're a monopoly.