I've not seen Crazy Rich Asians but I think I heard it was set in Singapore. Perhaps Chinese audiences just don't care all that much about Singaporeans. White Americans probably would not rush to see a movie about rich Swiss white people so there is no reason to expect Asians in Asia to necessarily care about a movie about other Asians. Asians aren't under-represented in their own countries so the demand for an all Asian Hollywood films probably isn't that high. I think Chinese audiences will see Shang Chi if it has lots of great spectacle and some big name Chinese stars.