Thanks for writing this response so I don't need to spend the time and efforts you did to write it :) Hopefully OP find it useful.
I'm in the same boat. I'm running the same Arch for 15 years now. The only cleaning is for old packages and config files. Also, if you remove the packages correctly, the maintenance should be minimal.
There should be no need to do a fresh install of the OS. This is another great benefit versus others. Even when I change my machine, I just install an image of my old system so it's fully functional right away.
Seems outside of what one would expect from a terminal. There's dedicated app to handle this task.