with the Chines, blame the Beijing OG.
As the host country has a team qualified in every discipline they started to conscientiously learn any sport they werent so proficient in. i suspect the results in some sports just show up 4 years later.
As about the focus on the gold medals, i can speculate that's a communist habit. It was the same in Romania before 1989. Even I can say about myself that it took me a lot of time to start to appreciate the other medals too
And there are things you can admire even outside of the medals.
The U.S. vaulter who came in 4th or 5th, did a super vault and stuck the landing. But, then he cheered and congratulated everyone who came after him and surpassed him. It wasn’t just a minor congratulations either, it was warm and enthusiastic. I was proud he was on the u.s. team just for that.
The Korean’s vault was amazing.