From https://promusicianhub.com/what-is-punk-music/
In its most basic definition, Punk music is a manifestation of the rebellious, anti-authority punk subculture that peaked in the second half of the 1970s, primarily in the US and the UK. Not just a music genre, but punk is more of an attitude, a philosophy, and a whole way of being.
Sure it doesn’t sound like punk music, but they sure as hell ripped a massive middle finger at authority.
As someone who has never heard of neither the band The 1975 nor their kissing stunts, it took me a couple of reads for sure.