If you're trying to find the key details in an incredibly complex/long piece (eg the Hammerklavier Sonata) to create your own interpretation, reading is just the best way to pick them up because the information transfer medium is a lot denser. When the musical "kernel" is simpler (eg a jazz standard that you improvise the complexity on top of), notation basically isn't necessary. Neither of the examples I gave is necessarily harder than the other - it's just about how much information transfer you need.

I will also point out that the best baroque violinist I know is blind, and there's a braille system of music notation that blind musicians work with.