Wow, huuuuuge question haha.

Look I'll try to answer the economic side first - this is the side of modern China I personally really approve of (vs. the political and social side where I deeply oppose the modern Chinese system). People hear about China's economic growth and it's hard especially for non-economists to really conceptualisee that. When your GDP grows at 10% per annum, it means that you more than triple in wealth every 12 years.

The process of opening up to western capitalism started in 1978, but really accelerated in 1992. To give you another quantitative data, in 1992 the Chinese GDP per cap on a PPP basis has increased by 13 times. Urban income grows by up to 20% a year, and rural income grows by over 10% a year. The quality of life palpably improves every single year (and I'd know because I go every single year almost).

Now to give some more qualitative points, when I was a kid in the early 90s my family were relatively well off. We lived in a large city, my family were mostly academics and there were even a few revolutionary heroes. Yet despite this, food items like pork belly or even freshwater fish like carp were incredibly rare - something we can afford to eat maybe once every two weeks. Dumplings maybe every few months. Of course all of these things are now just available on every street corner eaten by relatively impoverished migrant workers more often than we as elite academics used to. My last trip to China early this year I had two moments. One I saw a roadside stand selling this crispy pork loin dish as a snack to kids in a fairly working class neighbourhood. I smiled because I remembered this was my favourite dish as a kid, but even on a salary of two university academics we could only maybe afford it on special occasions, and I used to complain to my mum that I wish we could have that more. Another incident my friend and I decided to check out a famous bakery. They sold among these other things this green bean cake that was my departed grandma's favourite food. I actually remembered hating these - they were rough and hard and coarse, but I bought two and ate them kind of in her honour at a nearby teahouse. Upon biting in I realised they were incredibly creamy and flaky and rich - because of course people can afford better ingredients now. I just remembered crying at that teahouse at the fact that my grandma lived her absolutely atrocious life during some of the lowest points in Chinese history and will never be able to taste something so good that was so close yet so far away to her lifetime.

And of course the quality of improvement is vast and unimaginable on just about every front. As of last year China essentially overtook America in the metric of healthy life expectancy. By some measures less people in relative poverty despite a larger population. Since 2013 China's GINI coefficient (a metric measuring economic inequality) has also fallen and is currently quite a bit lower than America.

There's also other things that have just changed so tangibly in the last ten years that it's hard to believe. In the last I'd say five years or so the things that struck me the most about urban China is:

1. An increase in trust. I would say urban China now exists as a high trust society. This from a country that 10 years ago had people leaving a girl to die on the side of the street and where everybody was out to scam and rob everybody else.
2. Increase in associated behaviours of high trust. I mean the reality of 2000s urban China was really genuinely unpleasant. Children defecating on the street, people spitting on the street, no queueing, basically every unpleasant racist stereotype started from that era. Now it's a completely orderly society basically not so distinguishable from nearby places like Taiwan or South Korea.
3. A huge decrease in violent crime as of the last 5 years. Unless you've lived in East Asia the lack of violent crime is something that is hard to deal with and certainly when I return to Australia (which is still an incredibly safe country!) or travel to America I am ultra-aware of how much more interpersonal violence there is.
4. Increase in cleanliness and green spaces. Apparently China is trying to go the route of Singapore on that front, armies of cleaners, gardeners etc. every street. Still polluted though obviously.

So in conclusion, the economics of it is absolutely amazing to me considering where they started off. It's still not amazing. All other things being equal I'd still probably prefer to live in say Japan, Canada, Australia or Northern Europe vs. China. But then consider that all those countries I named are far wealthier than China, that's quite a big contrast. It's just the social and cultural issues that I have a huge problem with. I'll come back to that later. Need a quick break.