Many problems aside, they could just print or give money.
The Chinese government is not.
There's just some realities about global economics. Uruguay, Portugal, or Rwanda default, then they have a problem. China or US has the same issues, and it's just not the same kind of problem. They would just redefine things so that they don't default and then call the whole thing a "bailout". I'm not ragging on south americans or africans or portuguese, I'm just stating facts. It's not fair, but that's how the global system works.
You do business with China or the US, you find out fairly early on that even in a crisis, it's their way or the highway.
Economies and companies are highly interconnected. There is no magic wand to fix the problem without serious repercussions, even with an authoritarian government.
You wipe out USD debt holders, they will never lend to your companies again. You print money to pay off debts, you get inflation, weaker currency and potentially other destabilizing outcomes, like moral hazard of private sector expecting bailouts.
All debt problems can be solved via arbitrarily high inflation, yes. But it's also the setup for mass suffering and potentially revolution.