He won everything he could, and there was objectively no one for him to compete against. And Plushchenko stayed, because he really wanted that famous Olympic "gold."
This is a quote from Fireball.

It's absolutely right that Plushchenko stayed, because he's simply younger than Yagudin.
I haven't liked Alexei since he went to Tarasova, who made him a champion (at that time, she had access to the best training facilities), while Zhenya stayed with his mother in a communal apartment where alcoholics lived behind a plywood wall. Plushchenko forged himself, Tarasova created Yagudin, so as an athlete, I like Zhenya more. And he deserved his gold!!!!