Kbin is essentially the same as Lemmy.

I also would say I don’t think the graphic is correct about the way “all” works. I’m pretty sure “all” is content from all local and remote communities any local users have subscribed to (which is shaped both by local user activity by the federation graph that local and remote server admins control). Communities on servers that admins have defederated from will not appear in “all”.

So… individual local users and admins shape the “all” feed. I don’t think there’s any way to get a global feed of all Lemmy activity.