My theory is the higher grit we go, the thinner the fin gets. The thinner the fin gets, the weaker it is. So to avoid that it either needs less work or be fatter. To make it fatter, we need to change the angle. I’m not into complicated math, so I go the more simple route. It’s all theory and supposition though. I could be talking gibberish. I do have some razors with many shaves on them. I do not keep records though amd rely on me,pry, so it really is just theory.