Much like the US, they can simultaneously have an economy that SHOULD collapse, but also be so ingrained in global trade that nobody is actually willing to call them to the carpet.
If China were Greece, they'd probably have gone bankrupt multiple times already.
To be fair, out of all the billionaires they at least have made attempts to not make their kids shiteheads which is in stark contrast to most billionaires. At one point in time at least, they were only leaving $10m to each child, with plans to donate everything else.
Is that enough to live better than 99.99% of us? Absolutely. But it's also not: I can do whatever I want and buy whatever I want and never have to think about money again.