I am a great fan of Steph Curry, and there is much talk about his shooting being unprecedented and changing the game. My recollection is that Pete Maravich averaged 44 ppg in college, with no 3-point line. As he often shot from distance, even though one didn't get extra points for it then, people have gone back and examined game film to see what he would have done with a three-point line. An LSU coach charted every shot and estimated that he would have averaged 57 ppg. Even at that, we don't get a true picture. If he had known since grade school those long ones were worth more points, he would have taken more of them, and perfected those shots.
As a professional, he scored about 23ppg with a bad knee and in bad situations. Examination of those films suggest it would be 29 ppg on today's courts. But again, if he had been practicing from farther back all his life he would presumably have been better at it and taken more of them. His NBA career overlapped with the 3-point line for only one year. He was 10 for 15. In 2010 John Havlicek called him the best ball-handler of all time, and the Hall of Fame called him the greatest offensive force in NBA history at the time of his induction.
I suppose what's new is that so many do this now. One would think with Maravich in front of them as an example, the trend to three-point shooting would have permeated to middle-school level as far back as the 1980s. But even with Larry Bird coming in and hitting threes, the game changed only gradually. Identifying the corner 3 as the best point-per-shot was sorta kinda known, but teams and players didn't follow up on that until quite recently.