There were horrible problems that derailed progress, it's pointless to deny them. On the other hand, some of the suffering came externally, like sanctions and embargoes designed to make life miserable and induce the country to fail/the regime to collapse. Also military threats that depleted meager resources and made normal investment impossible.

What can be said is that, given this set of very difficult challenges, whether self-induced or not, the outcome, such as it is, is a commendable one.

I don't have a source for this, but my understanding is that much of the improvement in China's literacy rate came from the government's redefining of "literate" down to about a 1st or 2nd grade school level.

Still, I can't help but be happy at how so many people's lives have improved so greatly in such a short time.

Simplified Chinese made a huge difference. It's one of the few undeniably good things to come from the CCP, although adopting a phonetic alphabet might have been even better.

Japan was devistates by WW2 also, but they bounced back quickly. China being one of the most powerful (and richest) countries in the world is actually not that unusual considering world history.