Genres aren't meant to describe specific artists, they're meant to describe the similarities of sound/influence/etc. between multiple. It's useful for listeners to have a shorthand to describe a specific type of music, because, as a listener, you probably listen to more than one artist. Of course from the perspective of a single artist genre has 0 value...

I feel like genres are super useful if you want to find new music to listen to, the more generic they are the less useful they become. Alternative-Rock, Indie or Pop are the most generic and the less useful ones as a listener.

You're right that discussion about genre is entirely boring and useless. Genres are concepts used to facilitate communication about other things. It's like discussing the validity of words as description of something specific. Like yeah, maybe "cloud" won't capture the uniqueness of the thing you're watching in the sky, but it helps you talk about it to someone else because there's a mutual understanding of the characteristics of the things we call clouds.