Hi all
just wanted to share my two cents. I was completely self taught up to the first 12 years of my playing but eventually, I hit a sort of ceiling and no matter how much I tried I couldn't break through and that was when I decided to study music formally at a music college.
While I didn't learn much guitar there I did study more theory and harmony concepts but through that you teach yourself how to apply it on guitar so in essence its sort of self study/taught as well.
Well after going through all that I must say is that studying music formally does is prepare you for a career in professional music. Jobs like session for artistes, studio sessionists, combo orchestra, touring band etc. Many of these jobs require certain skills like sight reading, comping, etc, and while these can be self learnt, almost always these are the skills neglected when you try to teach yourself. It would require great discipline and structure to acquire these by yourself but still not impossible.
Just my two cents.