Thanks for your post, it's very interesting and also somewhat strange.
I've been on Steemit for months yet I've never even heard of these other platforms(other than dtube), and if I hadn't found this post I still wouldn't know about them and probably never would have found them.
Maybe I'm missing something but I suspect I'm not the only one.
How or where do people learn about these things? Obviously these platforms are unlikely to thrive if no one knows about them?