Yeah as a chef I only learnt how to dice, chiffonade, brunoise, batonnete, julienne and tourne all sorts of food cause it looks cool.

Different shapes and sizes is extremely important, it's why salt flakes taste different to iodized salt because of surface area or why a thicker slice of ham will taste different to a thinner one.

Also if you cant cut something consistently half of its going to overcook and half of its going to undercook.