I'm still learning the ins and outs of this place and the others, but part of me thought that was the feature of being federated. User accounts could seamlessly transfer from one instance to another.
Looking further into it, it looks like that feature exists for content, but not so much for accounts.
The thing that helps Kbin the most is that it is, by far, the easiest to understand. Googling "Lemmy fediverse" gives a bunch of various links to other Lemmy instances, which are presented in a way as if they are separated from one another. Kbin appears as one site, one location for content aggregation. Although that "goes against the idea" of decentralization, most users are currently looking for their "one home to replace their old one home". The more users flock to one area and learn how it works, the more things will begin to take their proper shape, so to speak.
Checking this out based on your recommendation and I already like it. Simple, no bullshit, and is similar to use to something like NewPipe but for desktops.