I don't worry too much about holding onto statistics til the end of time, but I do like having a way to be sure I cycle through most of my 10K+ tracks over time.
I'm VERY protective of my custom tags, though, many of which have been entered manually and losing them would be a huge setback.
For example, I like having playlists that I can let other people pick from to suit their tastes, such as when they're riding in the car with me. I'm still struggling with genre, but I've had pretty good luck creating playlists based on Billboard charts and decade. The fine details are more to satisfy my perfectionism and curiosity than for any practical use.
Then I have a whole collection of (mostly) industrial music that I use when I want to dance. I use play counts/dates, a custom tag, and a playlist mixer to turn MusicBee into a reasonably competent personal DJ.
One of the few "special collections" I have that's actually complete is the Bond themes, which have their own playlist and custom album cover view
. There are others in various states of incompleteness.
There are several other custom tags, some purely informational and some to help me keep track of my workflow and the status of certain files.