My home directory is magically growing, somewhere between a few bytes to a witnessed high of 50 KB every other second (possibly more when I'm not looking). I'm staring at this Get Info window, doing nothing else with my Mac, and seeing the number go up:
I'm on a MacBookAir6,2 (mid-2013) running Catalina (10.15.7) and this has happened before on a previous version of OS X. I then solved it by completely wiping the HD, installing OS X that came with the machine (pretty old), upgrading the OS in 2 steps because the upgrade mechanism changed and finally restoring from Time Machine, but that was just a few months ago. I don't feel like doing that every couple of months.
I've analysed some by doing du -sh * and du -sh .* in the Terminal (latter to get the hidden files/folders) but that only accounts for 18 of the 73 GB. So what is occupying the other 55 GB?
The du command does skip these directories with the error Operation not permitted, even when I do sudo du -sh *. Could it be some process that's accessing these ~/Library/[..] paths?
These are giving me the Operation not permitted:
du: Library/Application Support/MobileSync: Operation not permitted
du: Library/Application Support/CallHistoryTransactions: Operation not permitted
du: Library/Application Support/com.apple.sharedfilelist: Operation not permitted
du: Library/Application Support/com.apple.TCC: Operation not permitted
du: Library/Application Support/FileProvider: Operation not permitted
du: Library/Application Support/CallHistoryDB: Operation not permitted
du: Library/Autosave Information: Operation not permitted
du: Library/IdentityServices: Operation not permitted
du: Library/Messages: Operation not permitted
du: Library/HomeKit: Operation not permitted
du: Library/Sharing: Operation not permitted
du: Library/Mail: Operation not permitted
du: Library/Safari: Operation not permitted
du: Library/Suggestions: Operation not permitted
du: Library/Containers/com.apple.archiveutility: Operation not permitted
du: Library/Containers/com.apple.Safari: Operation not permitted
du: Library/Containers/com.apple.iChat: Operation not permitted
du: Library/Containers/com.apple.CloudDocs.MobileDocumentsFileProvider: Operation not permitted
du: Library/Containers/com.apple.mail: Operation not permitted
du: Library/PersonalizationPortrait: Operation not permitted
du: Library/Metadata/CoreSpotlight: Operation not permitted
du: Library/Cookies: Operation not permitted
du: Library/Caches/CloudKit: Operation not permitted
du: Library/Caches/com.apple.Safari: Operation not permitted
du: Library/Caches/com.apple.ap.adprivacyd: Operation not permitted

sudo du -hd1instead ofsudo du -hs *(not sure ifsudois needed, but in this case it doesn't hurt). – Gordon Davisson Oct 11 '21 at 17:24sudo du -sxg ~/* 2>&1 | grep -v permitted | sort -nr | head -n 20andsudo du -sxg ~/.* 2>&1 | grep -v permitted | sort -nr | head -n 20– Oct 11 '21 at 17:39