Huh? Seems this quote confuses correspondence and equivalence. A frequency f = 1 Hz = 1 s^-1 (aka cycle/s != rad/s) corresponds to an angular frequency ω = 2π r

Huh? Seems this quote confuses correspondence and equivalence. A frequency f = 1 Hz = 1 s^-1 (aka cycle/s != rad/s) corresponds to an angular frequency ω = 2π rad/s (ω = 2π f) but they're distinct concepts and quantities. The Hz was introduced in SI with all those considered. Basically both statements "1 Hz = 1 rad/s" and "1 Hz = 2π rad/s" are wrong. The only dumb is this quote tbh.