I love writing (to publish externally) and journaling (to keep private). However, things don't always fall neatly in one bucket. I just finished writing something I had every intention of sharing, but then something in me felt resistance. It was a moment of reflection just for me. And while I'm certain others would find it valuable, nobody else would feel the lesson as deeply as me.
I still benefitted by writing it and processing an experience of my life, but that's where the value probably ended.