Today, players are prepared much better, are stronger, faster and jump higher and higher. There are always players who exceed the limits, for example in the maximum jump height of the attack. Who knows, maybe one day I will see how a player will reach 4 meters with the jump. Coaches often push young players to be more mature and muscular as soon as possible, even before they are able to play volleyball. Players jump high before knowing the basics of the game, attack hard before being able to control the ball, serve aces before knowing how to serve to all areas. In easier words, they want to reach the adult pro level as soon as possible.
In my opinion, we shouldn't ignore the natural development of the player. Firstly a child learns how to walk, not how to drive. In first grade they learn to write and read not quantum physics. If a child paints, he/she starts with a drawing of a house, star, flower or heart, not with painting the Mona Lisa. The constriction of a skyscraper with 80 floors does not begin with the constriction of the twenty-second floor but with the constriction of strong foundations ..... and this also works in volleyball and in any other sport.
We have to start with the elementary things and then continue moving forward. There will be time for each player to grow and develop their potential.
The player will grow at every stage of his career.