Gen Z has redefined “banger”. I’m not old man’n here. It’s okay. Every generation does it.
We used to use “that’s banging“ quite a bit in the 90s and my understanding was the musically it was mostly used as “head banging” for heavy music. Again, don’t care how people want to define it today. I’ve still mostly seen it referenced to music that hits you a bit harder than most, but whatever.