Argh I wanna add an addendum to the shit I said about anarchopunk being the only authentic punk genre. Anarchopunk practices what it preaches, and typical punk bands of the time (before the dramatic shift happened) were hypocritical largely, which is one reason why the shift happened. The SHIFT i am speaking of, is many-pronged. Which I will explain each in detail. The establishment of the post-punk wave of music, hardcore punk, anarcho spirited punks retaliation, and the formation of pop punk as a subcultural identity. Essentially the hypocrisy of 70s punk and those inspired by it led to an upheaval, bringing more honest punk music.

Post-punk was by and large a reaction to the artistic aspects of punk music. To post-punk musicians, punk had the spirit, but also terribly formulaic, simple, and repetitive music of low quality. Through this motivation, bands experimented with sound more, took the punk ideology and brought it into an expansive range of expression. This is also where many huge subgenres came from, such as synth punk, gothic rock, jangle pop, no wave, and many others. This change effectively undermined the popularity of regular punk music and brought in a new period of "hey, I guess punk music doesn't have to sound unsophisticated or uncreative"

Hardcore punk artists were very familiar to the dishonest presentation of punk music in media, and rather than push against it in an overtly political way, they drifted into more insular territory, small venues, largely abandoning association with regular punk. they're hardcore. And through this, the spirit of punk that post-punk had tapped into to create more interesting music, was instead being developed further in more brutally honest expressions of emotion. Which these expression in hardcore led to the creation of emo, which is the same thing as hardcore etymologically, but even more personal and cathartic.