The Man with the Gold makes the Rules, i.e., in the long run, economics triumphs over politics, even if the two influence each other. As China diversifies wealth and economic resources into many hands, and thus many power-centers, inevitably a central authority cannot maintain control over politics. When and how the CCP collapses is the real question.
The Chinese people, including especially those who hold substantial wealth, have historical reasons to fear the chaos that would ensue without the CCP anchoring the system, even of that anchor is a millstone dragging them down. Uncertainty about what would follow (national disintegration?; back to warlords and constant civil war with foreign powers intervening?; how would economic structures and institutions work?; would a Chinese model of self-government work?) This will act as a brake, since many will have to weigh the advantages of “freedom” against potential anarchy. I find a lot of zigzagging and fraying at the edges more likely than a precipitous collapse.
The wealthy support Communist rule because the collapse of central institutions would be followed by economic collapse.
Current rulers don’t want democracy because it reminds them of the chaos of the Cultural Revolution.
If the regime disappears, there is no guarantee a democratic government will fill the vacuum.