Naaah, I absolutely don't believe the "all music is written" argument. There are endless possibilities to create emotions in music. The key is using different sounds to serve the purpose created for them, and combining different things creatively together so they feel as one song. It's like storytelling. See the thing is, music shouldn't be a sport, it should be art. So many metal bands treat guitar playing as a sport. Just because most people don't have creativity for shit doesn't mean someone doesn't create something really cool and interesting at times. Most people just can't tap into that creative zone. Even stories are investigated as formulas and structures, but it doesn't mean someone won't come up with something new or even something interesting in a natural formula. I could describe you an absolutely killer COB album moment to moment if I wanted to. And remember, atmosphere always feels fresh.
Simple composions can be incredibly amazing when there is creativity. And the most perfect song or story formula can turn out completely shit when the artist has no creativity.