It is said (by his acquaintances) that Chairman Xi is not a smart guy ("brain dead" is the word). He only has elementary to junior high level of education. Anything higher (including his "PhD") is fake.
His solution to every problem is fight (power struggle) until all your opponents are down. It may work in China's party politics but if taken to the international level, it fails. You can see this same solution being applied to the handling of Hong Kong.
He also believes that China is invincible because they have this massive supply chain thing which nobody else has.