I think you need a source on that one. Gun crime is obviously worse in the US - and an ongoing problem - but it's not a huge impact on quality of life for most people.
In suicide, China measures middle of the pack - certainly ahead of the US - but many Western countries do better.
In terms of "happiness" - China ranks quite low on the World Happiness Index:
I think that's an overgeneralization. There are many things that do "work better" or "improve faster". Mass transit and metropolitan cleanliness are good examples of this (with exceptions, of course).
However, the lack of a strong regulatory body for things like food quality and water quality still make it a much riskier place to live IMO.
That's not to say China won't, for example, achieve a one billion+ person version of Singapore in our lifetimes, but I still have a "wait and see" attitude towards this.
Note: I have lived in China and travelled nearly 6K miles by mass transit to all kinds of places there.
Do they publish statistics somewhere or is that based on their foreign deployments being relatively small?
I mean, if you can't expect that kind of service from the military wing of an unaccountable authoritarian maoist kleptocracy...why even have one??
However, air pollution, food safety, extremely high competition and fast-pace together make China a quite unattractive place to live and work.
Except for the drug control part: the police here seem to have pretty much given up on that.
If this is based on statistics, bear in mind that China does not report all crimes outside its borders (for face reasons) and even locally (so as not to disturb "social harmony").
This quadruple homicide was not reported on the news, likely for "social harmony" reasons as you mentioned. To me, this makes their external reporting of public safety quite untrustworthy (ironic, considering the video linked by OP).
Gun crimes are still dropping. Our coverage however is increasing. What I love is when people confuse gun crimes and gun deaths. Do you know what gets counted in gun deaths but not gun crimes? Suicide. But the USA gun deaths get related to the rest of the world's gun crimes. I will say we have a suicide rate problem. It's actually really bad. But when you hear people defend communists, the same group in any other country makes the Nazis look like amateurs when it comes to genocide... suicide does look like a decent option. To be honest too, I imagine eating a bullet is more attractive than hanging or bleeding to death. Anyways, every time communism arises, "We're all for peace and tranquility and to achieve that we must kill a lot of people who don't agree with us on a philosophical level and we pick a social group the majority will enjoy watching get killed." But oh, the communists are all about unity and peace and "philosophical expansion against imperialism and oppression" that is some how different from the standard definition of imperialism and straight up murder.