Why are there fewer and fewer traditional centers in NBA?

First of all, there are fewer and fewer players with physical conditions and skills. In fact, before the introduction of the three-point line in NBA, there were many traditional centers and many good centers, but after the introduction of the three-point line, hitting two three-pointers was equivalent to scoring three goals from inside, and the three-pointers were highly ornamental, so players tended to attack from outside more and more. In addition, in order to improve the enjoyment of the game, the NBA revised the rules again and again, such as 3-second violation, 5-second violation, changing the trapezoidal three-second zone into a rectangle, etc., which restricted the traditional center to a certain extent, so the players' skills are more and more inclined to the outside line.