I mean why would you bother. (Normal exceptions apply - people with disabilities etc who can't grate cheese).
How hard is it to grate cheese? Plus that ready grated stuff must be as dry as a bone.
Plus ready sliced cheese. Why would you now just slice your own cheese? What use are those slices anyway, they are thicker than a pound coin, you would choke on sandwiches made of that.
So expensive as well.