I was interested to read that you had so little engagement on your other blogs - being read by 500-1000 people, but getting only 3 formal comments. I see this on so many blogs. Why is that?
I 've got to admit that I've never left a comment on someone's stand-alone blog, because it seems like I have to register, or maybe I would never come back to that blog. It seems harder to even think of developing a rapport with a blog writer. I like Steemit and YouTube because the culture does seem to be lots of comments and connecting with people.
I think you already answered your own question, at least in part! :)
I'll add two general bits, though... the major blog carriers-- WordPress and Blogger-- are not communities. Your blogs there are essentially individual free-standing web sites that happen to be blogs.
The other bit is that most blogs are somewhat "static" rather than dynamic. They are not created and laid out in a format that invites discussion. Half the time, the comment feature itself is served by a 3rd party like Disqus.
On Steemit, everything is connected under a single umbrella... similar to social blogging sites of 12-15+ years ago.
It does seem that the culture of websites doesn't include much discussion. I think it would be disheartening to have 500-1000 and only a few comments. I can see from YouTube how important comments are to building connections among people, and Steemit sure confirms it for me. I appreciate your perspective on blogging, with all that you've been involved with over the years!