You mean Blondie ain’t punk? (Think songs like “Detroit 442”)
Blondie did rap, reggae, all kinds of stuff. Very versatile band. I disagree with the author’s basic premise that most people were locked into “one thing”. My recollection is that most people like a variety of things and that bands could shift from one genre to another. But genres were basically recognizable and distinguishable. For me, today, the commercial music all sounds equally bad.