Chinese parents are prepared to pay premium to buy in areas where there's a good public school.
If their kids are "book" smart enough they would've gotten into a selective school and it doesn't matter where they live.
If their kids didn't make it into selective, that's an alarm bell ringing to the parents. They will choose the next best thing.
For first generation Chinese parents who sacrificed their stable lifestyles to come to Australia to give their kids better opportunities in life (and may need to take on less desirable jobs due to language limitation and non-transferable qualifications), they usually pick a good public school over a private one.
They consider it better value to spend the money buying in a good public school zone and pay off a tangible asset (which is proven to appreciate over time) than dropping money on private school fees. It's less risky overall.
Over time this becomes a self fulfilling prophecy. More families who care about education send their kids to the local Public school, the public school overall performs better.
This is why BEecroft and Cherrybrook are so expensive in Sydney. Very far from CBD and not much else going on except there are good schools In the area. Chinese parents prioritise their kids' education over lifestyle.
Of course these are generalisations. Not every Chinese parent does this. The younger generation and those from more affluent background are more open to sending their kids to private schools.
Edit. I'm not a Chinese parent. But I know many. These are just my 2c worth of observations.