I think you are having trouble seeing the forest for the trees.
I'm not making the argument China was more advanced than the British Empire. I'm saying there is an ocean of difference between a country with it's own writing system and taxation, and a country that does not. Not everyone has a particle accelerator in there backyard but there is institutional knowledge baked into the society.
https://en.wikipedia.org/wiki/Minggatu
This is a real person that existed, they were not banging rocks together they were doing sophisticated mathematics, I'm overstating anything. It's not my description of China these are historical facts. One the communist party would very like people to forget because it doesn't suit their narrative. They failed with their planned economy and they persecuted their scientists and scholars for being part of the wrong class. They actively caused a regression where millions died from their incompetence. Credit where credit is due they have since corrected course to some extent.
And no I can't find out what the communist party is thinking by talking to old people in rural China. One they don't know, two most Chinese people are extremely Cagey about what they think, you need to know them for years until they trust you enough to talk about it if you are Chinese and even longer if you are not.
If your wife is Chinese it might do you some good to read up on what a primary source is and then go read some Chinese History.
I am Chinese myself, I did learn Chinese history, and I find the idea that China was — in your words, maybe not British Empire advanced, but "redeemably" advanced — and that things would have gone well if only the communists didn't ruin things, to be utterly ridiculous. It sounds like a post hoc rationalization to feed the goal of casting the CPC as bad, while ignoring the hordes of historical evidence and living experiences of people who can testify that the Republican era was pretty horrible and was in no way on track to growth and recovery without the communists. The Republic was a failed state. If those guys were so good then the population wouldn't have overwhelmingly supported the communists. Your dictinction between "the communists" and the population is entire artificial and goal-driven. The population at large were "the communists". They wouldn't have become so if everything else worked so great. Communism was chosen out of desperation in the hopes that it would save China, after everything else failed.
After 100 years of disaster, war and poverty, people needed time to figure out how to govern well, things didn't just happen and kumabaya with "freedom". If you think the Great Famine was uniquely bad, you should compare with at all the famines during late Qing and Republic.
When western allies gave Qindgao to Japan, completely violating any earlier agreements with the Republic, it enraged the population so much that support for the communists spiked. I find things really puzzling... the west helped create the communists' popularity, and when things suited the west geopolitically they would cast the communists as the good guys. Now that the west feels threathened, people happily forget the parts of history that don't suit them, and cherry-pick other parts to create a distorted narrative. Where's the intellectual honesty that they taught me at school and is supposed to be the heart of Enlightened ("western") values? Voltaire would be rolling in his grave.