So why aren’t the NBA scouts recruiting powerlifters, Olympic lifters, or strongmen?
At 6’6" in high school, I doubt you even NEED to jump. The important thing is first to be in the right place when you jump, then jump at the right time. That involves learning the game and practicing game-specific skills.
Sorry, I’ve seen way too many skinny, weak kids playing awesome basketball. And I’ve seen plenty of well-built kids who could move weight in the weightroom but couldn’t do a thing on the court.
You have only a limited amount of time, energy, and mental focus. So spend it where you’ll get the greatest result: basketball skills. In high school, for sure, skills account for 95% of basketball performance and weightroom numbers 5% at most. There’s no contest. If you want to be a great basketball player, you have to work on BASKETBALL.