You don't need to be that worried. China has not rewritten any financial rules. People backing the wrong horse and getting wiped out has always been part of the risk of investment. For example, Argentina have been wiping out creditors on their govt debt for decades through devaluation and default...boom boom.
China have been behind nearly 4 decades of global deflation, but that 's pretty much a thing of the past now.
Their growth chart has been heading in the wrong direction for at least the last few years. Are there still opportunities in such a large economy, of course. Are they worth the risk given the political and economic disruption of the last few years? For some people they will always be worth the risk, but notably more than a few well respected money managers have pulled the plug.
As I said earlier (your comment notwithstanding about so many people being clueless about Chinas economic future), I am better than 80 % confident that China faces decades of economic stagnation and deflation is the ultimate downside of nigh on 4 decades of above average growth. So many people underestimate the time frames for these issues to play out. For example, given the rocket like growth of US GDP post 1900 and the initial reaction that was the 1929 Wall Street crash who would have thought the US market would not regain it's former peak until nearly 1950 !! Yes 20 years plus of false recoveries and ironically WW2 probably helped that period to be shorter than it otherwise would have been. Japan following their boom were not so lucky and they have been struggling to escape deflation and stagnation for at least 3 decades plus.
History does not need to exactly repeat itself , for these economic behavioural patterns to make themselves known.