That question is based on a bad frame of analysis. Critical support for Russia is for the role they play in combatting the imperialism of the global north, and the strong ally they are to socialist countries. It isn’t at all because people think Russia is some paradise. Further, I can totally say that Cuba has a better economic model than the US despite quality of life being lower in some areas because of the circumstances Cuba is in, it’s under massive sanctions and doesn’t have the privledged position of world empire like the US does to give it vast quantities of wealth.

Put another way, your question makes about as much sense as “oh, you’re pro-Palestine? Why don’t you move there?” This is a classic fallacy targeting anti-imperialist and pro-socialist westerners, quality of life in the west is artificially inflated due to imperialism, not because the western economic model is intrinsically superior.

As for the PRC, I’d totally live there for a few years! I don’t speak mandarin, nor do I want to uproot myself to move there long-term when my family lives relatively close to me where I am, but for a short while it would certainly be fun! China is only going to continue improving over time while the west is going to continue to stagnate and die, so hopefully we see socialism in the west in our lifetimes.