I’m curious why you consider this beneficial — i.e., what is your use-case? Using a hidden collection for archiving is one application, but Bitwarden is about to roll-out a proper archiving feature. Potentially, I could see a way to use collections as a work-around for tags (a long-requested feature with an uncertain future). But other than that, why do you use multiple collections with single-user access (i.e., for non-sharing purposes)?