Unique identifiers made sense when notes were physical cards in a box. Navigation required a numbering system when the alternative was searching through paper. In a digital system, the title does the work. [[Note titles are APIs for thought]] describes what this means: a well-formed title that states the claim clearly becomes the link, and you navigate by language rather than number.
[[Evergreen notes should be atomic]] is the precondition. A narrow note with a specific claim produces a title specific enough to function as a precise reference. If the note is broad, the title is broad, and a broad title doesn’t function as a useful handle any more than a number does.