This guy has to be one of the dimmest folks I have ever seen. Putin straight tried to kill him, failed and the world did nothing and yet he still turned himself in as some type of martyr. The world was going to do nothing and they were going to torture him and trump up any charges they felt to ensure he never sees the light of day again and for what? Nothing.
He knowingly martyred himself. Martyrs can sometimes effect massive change. I wouldn’t have done the same, and clearly, neither would you. But it doesn’t make his decision dim.
Real life is far more nuanced than your pedestrian analysis.
So it would've been better to escape to the west and have all his work and ambitions for his country thrown into the toilet because he handed the "I'm just a puppet in the west" gift to Putin. That's more of a Yanukovych thing.