[2023] Paradox games won't launch on steam [MacOS]

Is your MacOS User Documents folder on your local disk, or has iCloud grabbed it? If the latter, that's a problem with the launcher at the moment - can you move it back?

If that's not the issue, then it's probably a file access/permissions issue in MacOS. Go to System Preferences > Security & Privacy. Then select the Privacy tab. Scroll down to files and folder in the left column. You’ll see a list of apps and the folders they need access to. Check the box to give access.

Allow accessibility apps to access your Mac

Specify which apps can access and control your Mac for accessibility purposes. support.apple.com