A hardlink is a (poor, partial) implementation of a tag in the file system. A tag will recover a collection of all the elements filed under the same label, and a link can't do that.
I think hard links could. To take the up-thread example, you have one folder called "Vacation2018", and another called "BestDogPics". The photo of your dog on vacation lives in both folders, but hardlinked together.
