I have heard some bad stories about that - But I think it's important to decouple the policy itself from the way it was enforced.

The policy is very powerful in at least two ways: Firstly, it allows parents to focus all their energy and resources on raising and educating a single child. Then secondly, because Chinese people have fewer children, the assets in China will be inherited by fewer people which means a higher net worth per capita for the next generation.