You can read only up to a certain level (not super high). Out of the context of music, it would be like thinking about learning to play Tennis to a very high-level just by reading books. It's just extremely unlikely these days. In Piano, you might find some examples here & there (hard in classical, but look more into Jazz)... but the reality is that those folks were exceptional.
In piano (but true for a lot of sports too), when you hit a certain level, it will be more about how to make a lot of things work for your body, your hands... the way you are built. Doing that alone is possible, specially if you had a lot of instruction before. It does require a lot, a lot of intuition and a very solid foundation. It's also easier with the appropriate teacher, or mentor/s I should say.
In piano (but true for a lot of sports too), when you hit a certain level, it will be more about how to make a lot of things work for your body, your hands... the way you are built. Doing that alone is possible, specially if you had a lot of instruction before. It does require a lot, a lot of intuition and a very solid foundation. It's also easier with the appropriate teacher, or mentor/s I should say.
Hopefully this helps you out a little?