I am fine with the basics (e.g. classical vs rock/punk vs pop based on instruments) but there’s loads of other terms that aren’t very intuitive.
What is the difference between “alternate” rock and I guess “regular” rock? What is the difference between rock and punk? What is post-(insert subgenre here, like punk)? What is pop rock (the music subgenre, not the fizzy candy rocks), and how is it different from rock pop? What makes music “progressive”? What on earth are the “blues”? What is the difference between rock, metal, hard metal, heavy metal, etc. aside from an increasing level of angriness and decreasing level of clarity? etc etc
It’s a language so that people can discuss varying levels of nuance with each other. You probably don’t care about the difference between industrial metal and folk metal, but metalheads certainly do. And even that’s a pretty top level example.
Same goes for every other genre/subgenre. Indie pop and bubble pop can be very different, and just because someone likes one doesn’t mean they’ll like the other.
There is also a historic factor in all this because genres are always influenced, derived from, or mixed with other genres. Triphop was born this way, as a mix of hiphop, jazz, dub, electronica, and many others
Tldr: Think of it as painters describing colors