XD joke aside, the metal damaging the knife is a genuine issue worth considering. The other two issues… arent negatives for steel as everything gets fingerprints and youll be touching it with grimy food anyway. And cleanliness is not jist a matter of soap and water, but cavities on a rough texture that can trap food particles which wont happen on steel.

But dulling your knife every time you cut is a huge concern and unavoidable on metal vs metal. Wood and plastic take the brunt of the cut instead so they take the damage but leave scuff marks that are again bacteria traps. So its still kind of 30/30/40 on which is best in the end. (Okay plastic is by far the worst, but its cheap)