In a way, in terms of audience, I currently think of my personal wiki as ‘me first’, although not ‘me only’. A personal wiki could be completely private, and that’s a totally legit use case. However for me having it public has a big benefit – sharing my ideas and learning from feedback is a motivator to writing for me. But I think of it as ‘me first’, in that if there was some pressure to make it really polished, I would probably hardly ever write in it.
I think the important thing is whatever motivates you to write, at the same time as removing the friction. That probably changes from person to person.