Why can't you imagine anyone do better?
It is easy to see all the good things that happened in China in the last decades, and see the things that work. But I can very easily imagine a better government in China, much like I can do so for the US and in EU countries.
The CCP is running literal concentration camps, is suppressing free speech, using (possibly) questionable economic measures, strongarming other independent countries, censoring and even harvesting organs of prisoners for profit (probably for political elites). And most of those things on a scale previously unimaginable. Furthermore, one might argue (and I am not saying this is black and white) that the process of raising people out of poverty has as much to do with technical progress, foreign trade and China's geographical and demographic makeup, as it has to do with actual policy (and one could therefore imagine even better outcomes!)
I think it is indeed very easy to imagine things going better in China!
That's the entire point, I think. Citizens should be willing and able to be unhappy with their governments, and be able to express this without disappearing. That you can not imagine anyone doing better in China is what the OP was talking about.
Edit: Just to make this clear, I do not want a discussion on the merits of the CCPs policies - everyone can have their own opinion on that - much like for any other country. But the worry is the well rehearsed narrative that China is somehow unique and requires, basically, an iron fist rule. This I have seen many times in discussions with Chinese - saying that all these criticisms may be good and well for other countries, but not for China. And this in the end amounts to unwillingness to question the CCP in any way. And that, I think, is not good.