To answer this question myself I have to go back a VERY long time. I have had several channels over so many years and the reasons I create content has always been different. For some channels it was to grow something that felt like mine and a space to let off creative steam which is what my main channel now allows me to do and I have also had channels where the focus was solely providing content in an under served niche and wanting to turn that into a viable income stream. Its always allowed me to create something outside of myself that others can enjoy whether for education or just plain entertainment.
What about you? Share your story of why you do YouTube?