The downside of those is that they a) don’t actually create a very sharp edge, but instead create a “toothy” edge that can’t push cut, but can slice decently, a

The downside of those is that they a) don’t actually create a very sharp edge, but instead create a “toothy” edge that can’t push cut, but can slice decently, and b) remove a lot of material, and thus shorten the life of the knife.