Why doesn’t Klay just shoot 3s since the defense lets him do it freely every time, is he stupid?

I think saying clueless or something to that effect is too mean, its more like wish fulfillment or regular fan delusion but the most common and egregious one is “if he learns to shoot” or “he doesn’t even need to learn to shoot” or some variation of it. This isn’t about any single player specifically although it applies to many now and in the past. No other sport has this kind of phenomenon, the most important part of the entire game and people treat it as a minor inconvenience that can be bypassed and yet every single year in the playoffs guys who are even mediocre and even average 3 point shooters are exposed and completely ignored by defenses and it works.