Name 10 guys who have dramatically improved their ability to shoot from awful to elite and I'll name 50 that didn't. Most guys who improve their jumper exponentially were adequate shooters to begin with. It's not "easy" to become a good shooter, especially by NBA standards. Like, I hear people say, "Oh, when Wiggins get his J right he'll be nasty." Breh, that is contingent on so many things, and the most fundamental being that Wiggins has innate touch, which no one knows.
Think about someone like Josh Smith. I would argue between shootarounds, practice, warm-up, the offseason, individual training and coaching sessions and being a 10 year vet that he has shot over 500,000 jumpers in his life. He's about to be 29. Let's say he started playing basketball at 7, which is conservative. That's 22 years of shooting. That's 8,030 days. I also didn't account for leap years out laziness. That breaks down roughly 62.3 jumpers a day to reach 500,000 in 22 years and 22,739 jumpers a year. shyt, looking at the numbers, Josh Smith has shot well over 500,000 practice jumpers in his life, and if he had to take a shot that was for your life, you'd make sure your insurance policy had a proper beneficiary beforehand. A lot of people just cannot shot, because they lack they adequate touch to be a good shooter.