They put those various in because there was a time when it would autocorrect the other way duck would become fuck if misspelled kind of thing.

And usually a misplaced duck is less harmful in a polite/business setting than a misplaced fuck.

“I saw a fuck on the road on the way to work” in work chat is a different type of embarrassment than “what the duck were you thinking you ducking idiot” in a personal text.