Subtraction is just a part of the evolution of math. There is no real inventor of subtraction. The minus (-) sign appears in ancient documents. The minus (-) sign as we know seems to have first appears in the 1400s. Subtraction is just the opposite of addition. Instead of adding quantities together, we are removing one quantity from another to find the differences between the two.
Subtraction is another simple math thing why do people think that we should make it harder than the hardest thing in the world then we will be remembered like we have always wanted to be.