> Courts do not require a literal monopoly before applying rules for single firm conduct; that term is used as shorthand for a firm with significant and durable market power — that is, the long term ability to raise price or exclude competitors.

https://www.ftc.gov/advice-guidance/competition-guidance/gui...

Presumably the DoJ wouldn't have sued Apple for being a monopoly if it was impossible for them to legally qualify as one?

https://www.justice.gov/archives/opa/gallery/justice-departm...