Monterey moves all your desktop files to a folder - Don't try stopping the icloud drive syncing
Just upgraded an older laptop to OS Monterey yesterday. It is really dumb that it moves all of your files from the desktop into a folder. I didn't ask you to do that apple. That's not intelligence. That's over-reach. It then asked if I wanted to sync my files to iCloud. I thought sure, that's a great security measure. Well, unless you have up to 2 TB of files already up there, then it doesn't just sync files up to iCloud Drive it syncs all your desktop files from your other computers and from iCloud down to that computer. It starting filling up my desktop with thousands of files and was going to fill up more than all the memory on my computer, so I clicked to tell it to stop. It asked if I wanted to delete the synced files and me being an ordinary human assumed that meant the files it had just been syncing from iCloud. Well, except that it also deleted the folder of my 124GB of previous desktop files. I was livid. Took me a day to calm down. I knew better than to restart my computer or let the battery die since that can clear out temporary files upon the next boot. So instead I came back to it today. I logged into iCloud.com and there indeed is a folder named with my computer and desktop but it only had 3GB out of 124GB. Another deep breath. So I started fishing around my hard drive through all the folders. What a relief when I found a folder under: Macintosh HD > Users > Yourusername > iCloud Drive (Archive) and in there were all the files that had been deleted, including the desktop folder from the Monterey update. I hope this helps someone else who goes through the same thing.
MacBook Pro 15″, macOS 12.5