Lol you lemmygrad people hate hearing from people who have actually lived and worked in China.

If he tried to buy an airplane ticket it's possible he would have been denied. Riding a jetski across open ocean is pretty dangerous and not preferable. Also, there's no guarantee that you will be allowed entry to your destination. Risky move all around. Especially because the Korean island of Jeju has visa-free travel for Chinese passport holders. So maybe it was a stunt but... Risky move.

Oh speaking of passports, China stopped issuing new passports in recent years. I am not sure if they started back, but it was definitely an issue during the Shanghai COVID lockdown, as rich Chinese people were trying to leave and lay low elsewhere. It's possible that the guy's passport expired and he had no way of traveling by air.