I'm a musician, and am fluent at sight-reading. My perspective doesn't even consider the pro's and con's of conventional notation. The network effect is overwhelming.

Written music involves a symbiosis between the composer and the performer. You have to find people who are willing to do both of those jobs, in sufficient number to make performances happen. If you choose a new or idiosyncratic notation system, nobody will play your stuff.

In the future one could imagine automating the process of converting from one notation to another. But a lot of sheet music is still not in computer readable form. From what I've read, OCR'ing sheet music is still an unsolved problem.