I’m not a physicist, nor do I play the abacus (if that makes sense to you, you have my sympathies), but consider the following.
Regardless of the material that you’re cutting on:
- if the knife doesn’t scratch/mar the surface, the surface is as hard or harder than the knife edge, which can’t be good for said edge
- if the knife does scratch/mar the surface, there will be microscopic residue left over from the cutting, which will become part of the chopped/sliced food
If the above logic holds true, I’ll stick to wood cutting boards. Properly cleaned. Once in a while.