The men's field in the USA was not deep back then. (If Jason could make the Olympics team without a quad, it just shows that American men overall were pretty weak.) Even then Jason did need some luck to make the team. (He became a star due to his performance gone viral. This doesn't happen to anyone.) The men's field in Japan is deeper. Staying junior won't help Sota make the Olympics team. He already has enough (2 season) junior results. He doesn't need any more junior medals. (A junior world title would be the only title lacking. But a junior world title is not a must have either.) What he needs is senior medal and more exposure at the senior level. Even with his jump struggle, Nam is better off staying senior than junior. Right now neither Sota's 3A or 4T is consistent. If either of his 3A or 4t becomes consistent, he will get better results. Sota is the future of Japanese men's skating. I assume JSF wants Sota to have some experience at the 2018 Olympics, so he has a better chance to win the 2022 Olympics.
IMO, Yuzuru is definitely more talented than Sota. I don't think there is anyone that is more talented than Yuzu. Yuzu had everything at that age. People tend to think Yuzu is not strong in stamina, but Yuzu didn't lack stamina for his age (even when he was young). He only lacks stamina when he is trying to execute very difficult programs that nobody dares to try. The junior boys today all have talents, but none of them is as all-rounded as Yuzu at the same age.
I think Sota's main rival is Nathan. It's a bit unfortunate both of them got injured and ended their season early. I think Nathan-Sota rival is similar to Shoma-Boyang rival. They are the same age and both will turn senior at the same time. (They even share the same fate.

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