Big Sur, Finder Window, the Desktop favorite is gone from Finder Window left-side Favorite locations.
After updating to 11.4 from 11.3, the Finder window no longer displays Desktop Favorite in left Fav location navigation.
Mac Pro, macOS 11.4
Question marked as
Don't know why it would have disappeared but go to Finder menu > Preferences > Sidebar (at top of Preferences window) and put a checkmark in front of Desktop.