Idk. I blame Apple, and Android hasn’t done much to really bolster the need for file folders (not a bad thing, just lack of opportunity for learning).

But Apple actively prohibits its user base from engaging with folders, and has been for well over a decade - plenty long enough for my (millennial) generation to phase it out and for the generations after to never need them in the first place. Plus, emails aren’t dependent on file paths, whereas systems file paths are completely necessary.