I know there is a bit of drama surrounding lemmy right now, but in my opinion, kbin isn't really mature enough to self host. They don't have a good Docker environment, and while their docs have some Docker instructions, the process is fairly manual. If you're a beginner to self hosting and need help, kbin is not for you. And by their own admission:
This is a very early beta version, and a lot of features are currently broken or in active development
Conversely, hosting Lemmy is pretty much effortless if you understand the basics of Docker. And their docs are pretty good too. Their Caddy stuff is incorrect, and they could definitely use some help in automating the process, but it's much easier to get into than kbin.
Honestly, I'm not sure. I keep seeing people talk about "political views of the lead dev," and I see this a LOT, but no one has stepped up to actually explain what they're talking about. If you find it, I'd appreciate a link or something. I'm sure it's there, I'm just too lazy to go digging.