Lemmy, kbin, Mastodon, Misskey, Pleroma, Friendica... They all use different APIs, and those APIs need to be supported separately by developers if they want their app to be compatible with all of them.
ernest is talking about changing the kbin API to be more in line with lemmy's, which would allow apps made for lemmy to also work with kbin, but they wouldn't, for instance, work with (or possibly even know about) kbin's microblogging feature.
I'll be honest, I think kbin's microblog feature needs work. It either needs to be integrated into the lemmy style posts somehow or needs something else fine with it. It's pretty confusing how it currently stands.
It needs to be in the sidebar of magazines. There's no way to directly integrate it other wise, as they're totally different formats.
But there's a lot of potential in having the fedi microblogging stream at your fingertips. A not insignificant amount of Reddit is screenshots of Twitter posts. Being able to directly quote Mastodon posts to promote them to a thread would be pretty powerful.
But, you know, it's a very young projects. The developer hasn't had the time to integrate things