Xi may not be as much in charge as he believes himself to be. Yes, he's the Chairman, but if he fucks up too much, can he be booted?
Xi is the first leader since Mao to be both General Secretary(basically chairman of the CPP) and President(leader of the state). To remove him as President, you would need the consent of the General Secretary(himself), and to remove him as General Secretary, you would need the consent of the Politburo.
Since Mao, it had always been the rule that the General Secretary could only serve 10 years. Over 10 years, a General Secretary appoints all the Pulitburo's Standing Committee, and therefore would be almost impossible to remove after 10 years. Xi has broken this rule. He has only his closest allies in the Politburo's Standing Committee.
So to legally remove Xi, his closest allies would have to betray him. It is a multistep process that would take weeks or even months, during which he could, and would, have the plotters against him purged. To illegally remove him would require a coup in a nuclear armed country with a population over a billion people that is key to the world economy.
There are two other ways Xi could lose power. He might resign, but given that he failed to resign when he was supposed to (after 10 years), there is no counting on that. He will definitely die, sooner or later. That seems like the most likely way Xi will leave power.
Here is where things get ugly. Everyone in power in China is there because of blind loyalty to Xi, and "Xi thought". Without Xi telling them it is OK to tone it down a little, "Xi thought" might go completely out of control.
I keep coming back to the fact that two or three years ago, I would have told you there was no way that China could have purges anymore. Right now, China seems to be having a slow motion, quiet purge where more and more business and military leaders are being disappeared or even openly executed. Foreign executives are being arrested, even though they are not Chinese citizens(and investing in China which China should like).
It seems like a toad boiling thing, where the temperature is turned up so slowly that the toad does not even think to leave the pot.
As for Trump, anyone stupid and/or delusional enough to set up 1/6 is stupid and/or delusional enough to believe all kinds of crazy shit. Him being able to turn his delusions into reality is a completely different matter.
I really do not know. There is a huge amount of tradition and inertia behind American democracy, so I certainly see what you are saying.
Let's just say I am less confident that it is impossible than I used to be.