Directories are just a method of breaking the collection into usefully small / specific subsets for humans (mostly) and computers (a secondary but important performance optimization).

There's no technical reason some form of Standard couldn't be added to, or on top of, a filesystem that added tags as an alternate view or foreign index against the data.

The holdup is that there isn't any single standard for adding or searching by tags. The current directory structure is the lowest common denominator and has existed for longer than many of us have been alive. Change is _hard_ and those file open/close dialogues and interface methods still have to work, and they can work, at least for limited numbers of tags or maybe by some addition / removal special path syntax... However then it's stupid hard for the humans. Hard for the use case the tags are supposed to simplify.

Maybe this change can be added to what everyone really needs: a set of GUI calls that work on all the platforms, that isn't writing a damned web-page and using a DLL-hell-bloat bundled web-browser to do the cross platform lifting. Something that can work across all the desktops (as a target) and maybe all the mobiles (as another target) and maybe tablets too (slightly different target, somewhere between).