Fully agree with your general point, but Kyrie is an exception to that rule, no? He's not at all monomaniacally focused -- to the contrary he's in a constant state of narcissistic distraction.
What Nighthob said but I'll just say if you read about Pritchard, you will get an inkling of how much work athletes at this level put in. I mean I'm sure they enjoy the work - or at least the beating everyone - but Pritchard, just for one example, home schooled so he could go to the gym two or three (or more) hours every day and basically stopped having a normal social life from something like age 11 IIRC.
As Scalabrine said, professional athletes generally have this extra motivation - or narcissism, if you will - that the rest of us just don't have. From this article -
https://www.mcall.com/news/nation-world/ct-aud-nw-nyt-worst-nba-player-better-than-you-20210419-dhyabjli55gu5deifhfdtjg2fa-story.html:
End-of-the-bench NBA players may even have to work harder than stars to stay in the league, because one missed assignment could be the difference between having a job or not.
“I can go into any gym right now and I can find some of the best players going through the motions sometimes,” Scalabrine said. “Can you imagine 15 straight years? Maybe even more like 17, 18, straight years of never going through the motions?”
He said professional athletes, even retired ones, had an extra gear that an average person could not tap into. He referred to it as the “dark place.”
“I would always say things, like in a game, ‘If I miss this next shot, my kids are going to die,’” Scalabrine said. “I would say that to myself, just to get through, just to put the pressure so I can lock in and make the shot.”