Even contacts on iCloud is a mess. I can very easily, using only built in apps and set up, share a calendar, a todo list, a photo album, a music playlist, a no

Even contacts on iCloud is a mess. I can very easily, using only built in apps and set up, share a calendar, a todo list, a photo album, a music playlist, a note, an e-mail account etc. with my wife. But I cannot share a contact list with her without resorting to complicated CardDAV setups.