I would also much appreciate an archive function.
Specifically the archive should reside within each notebook for any notes of that notebook that is archived.
Moving notes or tagging notes doesn't resolve the clutter problem and risks losing the primary benefit of the notebooks (centralized organization, and 'seamless' approach to organize). The suggestions here are workarounds but they don't solve the primary issue.
I easily make hundreds of notes in a given notebook. As I know some notes are no longer relevant at a point in time I'd like to remove these so my notes are relevant for the tasks at hand. Consolidating notes into an archived note for a notebook resolves the clutter problem but i lose the visibility of the notes being viewable form a high-level since now multiple notes are buried in one card.
Feature function design: right click note> archive
Creates an archive sub notebook that contains the note.