They have something here called "fette biscottate" (literally, twice-cooked slices) which is like dried toasted bread in little squares. They aren't sweet (no sugar in them) and aren't very tough - in fact people often eat them for breakfast with butter and jam, dipped in coffee, and it's complicated to spread them without breaking. I wizz them in the blender for breadcrumbs. They sell breadcrumbs in practically every store, but they're made in store and sometimes are stale. These zweibach things (the fette biscottate) tend to stay fresher in their packaging and i can keep them on hand. I suppose croutons that are not seasoned would be the same. (I crumble them sometimes for stuffings).
I find that artisan bread dries too hard to grate easily.
And other kinds of bread get dry but sometimes moldy - and anyway, whenever i';ve saved rolls and stuff they usually taste stale.