I have a M1 MBA and a 2019 27" iMac. Neither of these were having any problems until a few days ago, when both showed big signs of memory issues.
[Examples]
Numbers (with 2 speadsheets open): 7GB (typically 500MB with 8-10 open)
Mail: 4GB (typically 400MB)
Doing research this appears to be a Monterey issue, not a M1 issue. Several instances on the web state that this is a known issue for Apple and has been fixed on Monterey 12.1 beta. I have installed it and so far for the past few hours, no problems anymore.