Hello, you might have noticed (or not) that posts from kbin, more specifically kbin.social aren't showing anywhere, this is due the DDoS protection they currently have on. So even if you are subscribed to kbin.social communities you won't see any posts from the outside.
Same is happening inside kbin.social where users there cannot see posts from the outside. This is however temporary and the admin is working on getting federation back online.
~~The site is currently reporting 125k registered users~~
Edit: After a quick chat with the dev group it seems this number is just the total users discovered by this instance. The real amount of users is 22k as seen on https://kbin.social/nodeinfo/2.0
Edit: kbin.social is currently upgrading servers to handle the requests.
Joining is immediate, where some Lemmy instances require manual approval even now.
The main page comes off as more approachable and familiar. They also have a ton of local communities (or "Magazines") so people can do a lot even without the Federation. I find the Microblog stuff somewhat confusing, I think because it doesn't have much of a UI built around it so it is less familiar than Mastodon. It is fairly centralized though, in the sense that there aren't that many kbin instances out there.
This is also due to its age, its only 2 years old and only just recently gained more than 1 contributor to its codebase. When the reddit migration started about 2 weeks ago, kbin considered itself still in alpha; with lemmy in beta. As the software matures, more instances will pop-up as admins gain confidence in it.