The path for your iPhone / iPad backups on OSX Monterey (and presumably others) is:
~Library/Application Support/MobileSync/Backup
You won’t be able cd into that path using terminal because (I believe) the directory is protected. Even with SUDO I hit a wall. Instead, use finder. (I know, right?) Open finder, then Go -> Go To Folder -> then paste that link. Your device backups will be burried in apple’s classic gibberish UUID folders and filenames.
Mess with your data and backups at your own risk!!