Question

why do all cutting instruments have sharp edges​

Answer 1

to create a less surface area ans huge amount of pressure

Answer 2

Hola mate here is your answer :-

The cutting edges of tools like blades, knives etc., are provided with sharp edges to cut the things easily as the sharp edges has small area on which the force is applied, hence more pressure is applied.

Hope it helps!!✌✌✌✌