I prefer kbin as well, but I’m fine with colloquially lumping it all under “Lemmy” at the moment. It’s weird to wrap your head around the fact that all the different platforms can talk to each other, not just instances of the same platform.
People use the email metaphor a lot, but it’s sort of incomplete. It’s kind of like if, in addition to having different email providers, a few other communication services were built on email too (like instant messaging) and had varying levels of interoperability between email clients and chat clients. If “Lemmy” is the “Kleenex” of Reddit-like ActivityPub implementations, then so be it, IMO.