Until recently, I was routinely experiencing a very annoying bug/design flaw in macOS Monterey running on my M1 MacBook Pro. External hard drives connected via the USB-C port would sleep after around ten seconds of inactivity, causing them to be constantly spinning up and spooling down. This was evident with both an older 3TB Seagate desktop drive, connecting via USB 3.1, as well as a Lacie USB-C drive, connecting (presumably also) by USB 3.1.

No amount of changing sleep parameters in System Preferences, nor fiddling with pmset, would alleviate this issue.

However, having upgraded now to Monterey 12.6.7, this issue seems to be resolved.