Though it may be hard for basketball players or fans to now believe, the 3-pointer did not always exist! The 3-point line was not added to the NBA until 1979, to the dismay of most players and coaches. They did not want to completely change the way that players were trained, plays were run, or points were scored.
However, fans loved the 3-point shot! They were amazed that players could make shots from so far out and they loved that games could be won by more points. The shot became a staple of the game over time and something used by teams to win games. It is not uncommon to see players make a double-digit amount of 3-pointers in a game, but that would have been outrageous in 1979! As the game developed and players became physically and tactically stronger, the 3-point shot became one of the most important in the game.
Distances vary based on the average strength and power of players at their various stages in development. Since high school players are not typically as strong, tall, or athletic as players in the NBA, the line is not as far out and players can reach it more easily.