I am mainly a self taught musician but I had a smattering of formal music teaching at school and have built on that through books, internet and asking people who know more than me.

I agree that reading the dots is a useful skill and gives access to a vast array of materials, and I am working on improving my sight reading. However, now I am singing in a band where we do a lot of 3 part vocals I can also see the value of being able to jot down harmonies etc that we have found through improvisation n messing around. That means we can capture the best bits and then learn them accurately. It makes rehearsal much more straightforward. This is much easier than scratching our heads to try and remember what we did last time that sounded so good. We don't do it with every song, just the ones that are harmonically a little more complex.

So for me, music by dots plus music by ear (and improvisational skill) is more beneficial than either on their own.