Why do you have to rotate when playing a game of volleyball?

Answer 1

• you need a different server every time or it's unfair
• you don't want your teams stacked (setter, hitter)
• that's how the game works, it has to have some kind of spice for example, why do you change the batter in Baseball hmmm?

Answer 2

so you can play from different bases. the back row players can play front row and hit.