Hazel

Hazel is a Finder-shaped rule editor for the folders you would rather not police yourself. You point it at Downloads, tell it that any PDF whose name contains an invoice number should be renamed and filed into a dated folder in your archive, and from then on that happens without you. The rules go as literal or as clever as you want: match on file contents, tags, date added, the pattern in a filename, or hand the file to a shell script or a Shortcut and let that decide. It also uninstalls apps along with their support files, and empties the trash on a schedule.

Forty-two dollars buys the current major version for one person; the family pack covers up to five people in a household for $65. When the next major Hazel ships, owners pay $20 to move across, so treat this as a small recurring cost every few years rather than a single payment forever. Skipping an upgrade costs you nothing but new features.

Two reasons not to buy it. It needs Full Disk Access and Automation permissions to work at all, so it is a poor fit for a locked-down work machine. And if your Downloads folder has nine things in it, this is machinery you do not need — a smart folder and ten minutes of tidying will do.