Take a look at your fingers as the wrap around a handlebar...
Correct: pretty square.
This is why we have adapted our grips to this shape and created an ergonomic hexagonal wave form that fits perfectly in the hand and provides an ideal secure grip for the hand.
Do the test yourself
Check how well you can grip on something round,
for example a glass...
...and how well you can grip on something square,
for example a table edge