In addition to being able to hear the flaws in my playing (at least I can hear those with come clarity), when listening to a song I've recorded I can also hear the chords as chords, without the intervention of my fingers which play individual notes. I know what the chords are, because I came up with them and played them, but I couldn't identify them as such if someone else were playing them, so I can hear them more purely, as colors.
If I can hear what I'm doing wrong with some precision, then I can correct it. I can hear that connections can be more legato, or that I rush in certain places, or hesitate too long for a fermata. Isn't listening a more important skill than playing, then?