I think that this is the incorrect way of looking at it. I suspect it is less that the traditional notation system is highly evolved and effective, and more that getting a critical mass of musicians to transition/relearn/teach/translate into a newer system is incredibly difficult.
For instance, while Imperial units aren't without some advantage, they are pretty generally inferior to the Metric system. But the US hasn't really switched because it requires a significant level of coordination and control that simply isn't easy to access. And getting musicians to learn and teach a brand new, objectively better system would be much much harder.