Evergreen notes should be densely linked, and if you follow the advice in Prefer associative ontologies to hierarchical taxonomies, you’ll find it’s easy to navigate along trails of related ideas. But if several notes are related topically, or related through another note, it’s difficult to navigate between them by the in-note links.
One example: if you have many small notes about techniques for solving problems in cloud systems, it may be helpful to see those “neighbor” notes when viewing a particular note. They’re not directly related, so it doesn’t make sense for them all to link to each other. You could make a “hub” note called “Solving problems in cloud systems” which contains links to all those notes, but you still wouldn’t be able to see those neighbors from a given note. You lose the Peripheral vision of the backlinks section—you’d have to navigate to the “hub” note first.