Two on two play. The court is narrowed and players are only allowed to tip the ball on the other side (spike forbidden).
By playing on narrowed court players must adapt and control ball power and direction. Using fingertips gives them a weapon which may be used during regular matches to baffle rivals.
New hitters rarely miss because of their arm. They miss because of their feet. Build a reliable approach, then time it with your setter.
When your hitter gets stuffed, five teammates standing and watching is how you lose the point. Good attack coverage turns a blocked ball into a second swing.
Coaches spend hours correcting arms in serve receive when the real fault is almost always the feet. Fix the movement and the platform fixes itself.