Your view of China has been trapped in Chinese propaganda.
Funny, because I was stuck in Hong Kong for a couple of weeks during the 2019 riots. Was it Chinese propaganda when the students were waving big "Trump 2020" banners?
I would not say that the Chinese that are living a lavish life with a lot of luxury are living a socialist life.
I wouldn't say this about anyone. It's not "luxury" if everyone's enjoying it. That's sort of the joke of socialism. It's a basic standard of human comfort, not a lavish expression of artificial scarcity. One day you wake up and there's cheap abundant cavier and 1 carat perfect clarity diamonds at bargain basement prices. Then they're not delicacies reserved for the privileged elites anymore.
They might be an example of how “capitalism makes people happy”
Sure, if you ignore that the Maoist uprising against the landlords was the largest and most comprehensive proletarian revolution in history, and led to almost totally-equal redistribution of land among the peasantry.
When wealth isn't being ruthlessly consolidated and surplus value vacuumed up from a powerless working class, its easy to walk down a main street in the Futain district and think "Wow, we've got Toys'R'Us in the states, too! I guess they're just as capitalist as we are."
Only problem is that Toys'R'Us doesn't exist in the US anymore, on account of a leveraged buyout and subsequent bust-out of the business. Commercial practices that would get you run out of town on a rail in Beijing are how you get rich quick in the States.