Almost all young prospects enter the league with the same weakness: They can't shoot.
Sometimes, it takes guys five years to develop a consistent jumper. Some never develop one at all.
It's especially important for guards. Think about it—a jump shot is essentially a counter to rim protection. Since it's tough for 6'3'' guards to pick up easy points in the paint, a balanced outside jumper becomes a higher-percentage shot.
For players who can't create their own shot, a spot-up jumper increases their scoring opportunities without the ball.
Without an improved jumper in the repertoire, none of the following players will ever maximize their potential.