We need backlink functionality, including:
- The ability to create backlinks without pulling up an entire second note (cf. Obsidian)
- The ability to follow link paths in either direction
- Charts/diagrams that show us link relationships at a glance, with the ability to select siblings, parents, and children at any depth desired
- Lists within each document (perhaps as a context menu function) to show all bidirectional "neighbors" at a selected depth...with options to preview or open those notes
Evernote apologists have tried to make the case that Tags serve these functions...but I think you can see that some of this functionality would be awkward (or impossible) to replicate with Tagging as it exists now in Evernote. That said...some of the same ideas I propose here could well be applied to Tags, making them far more useful.
(could Tags ever eliminate the need for backlinking? Normal tags are non-hierarchical, so they could not. But the Nested Tags of Evernote are a different animal...and with more robust support, could conceivably serve the same purpose)