I think when the highest quality most respected China collapse preachers say collapse, they mean entering a Japan style stagnation. I'm not sure, because that would require me to consume a lot of China collapse preacher content, but I think that's how they can justify the narrative across different levels of seriousness.
Even that narrative is fundamentally flawed because Japan's stagnation in the 80s was a direct result of US imposing Plaza Accords on Japan. There is no opportunity for US to do the same with China.
If China can manage to turn its industries and markets to an internal production/consumption model and reduce its reliance on being an export economy, it would be much better off even without the massive growth. Growth will have to stop at some point, and the focus will be on stability, since China hasn't made any indications it'll try to fuel growth through imperialism like western economies have. Japan style stagnation would be not so terrible if your society is socialist.
Even with the current model of state directed capitalism, the amount of investment into social services and poverty reduction already shame the west. China isn't yet in a position to press the communism button, but once the threat of America and it's puppets decline there may well be a pivot.
i think america is the main reason they still have shitty work conditions. i mean they still are better then the U.S. but it's sort of the inverse of the U.S.-Soviet competition over working conditions