I agree with your broad assessment that the glory days of Hollywood are over, but am not quite as optimistic on the future of Asian cinema.
Chinese media is crippled for the foreseeable future by heavy state censorship, including micromanagement of plotlines: can't do anything that lets the bad guys win or shows the state in a bad light.
I also note you don't include Japan, which is rich and has a population of 100M+, but with the arguable exception of anime has not produced any global blockbusters in decades.
China's movies have peaked in the 90s. Take a director like Zhang Yimou, he hasn't made any decent movies in the las 15 years because of state censorship. None of his best movies could be directed today: To live, Ju Dou, The Story of Qiu Ju or Raise the Red Lantern. The same with Chen Kaige or any of the great directors in Mainland China. Even a relatively recent movie like Beijing bicycle would not be possible today.
Even if a lot of those movies were banned in China on release, there were much less consequences for a director of a banned movie than nowadays.
Lol yes, I'd say the release of Heroes is precisely when I date Zhang Yimou's fall. The photography and use of colours is great for sure but it's his first movie with a mostly empty story that tries not to ruffle anyone.
Chinese media is crippled for the foreseeable future by heavy state censorship, including micromanagement of plotlines: can't do anything that lets the bad guys win or shows the state in a bad light.
I also note you don't include Japan, which is rich and has a population of 100M+, but with the arguable exception of anime has not produced any global blockbusters in decades.