I have multiple folders of the form "desktop crap MM-DD-YY"

Anything more than 5 dir deep is overly complex.

All movies are thrown into one folder called movies, every show is in its own folder with a season per folder. Jellyfin deals with that.
Music is stored by artist and thrown into the music folder.
Documents are sorted by year and purpose but are all in one folder called documents.
Books are in e-books, audiobooks are in audiobooks folders by author.

And more importantly, how do you back up your important stuff?

More the latter, I organise mostly by type (movies, series, music, podcasts, comics, books, photos, images etc) and use (workfiles, documents, resources, tutorials etc). There's was a whole subreddit about this, datacurator, not sure if something similar exists on Lemmy.

File trees 100 folders deep lol. I keep all stuff synced across my machines, no actual backup though...

I sort things every once in a while but eventually lose interest or patience. Would be nice to have a way to do it automatically. I suppose llms could help there, but I'm not sure if they're quite there yet in terms of reliability.