I would call writing one of the most underrated skills overall, not just for successful people. In fact, I'd extrapolate "write" to "communicate" since the same

I would call writing one of the most underrated skills overall, not just for successful people. In fact, I'd extrapolate "write" to "communicate" since the same thing applies to the spoken word, not to mention other ways of communicating (except that speaking and writing are probably the most commonly used). I'm constantly amazed at how bad some relatively smart people are at writing in particular, let alone communication in general. Getting good at writing is hard, and takes lots of practice.