Russia standard of living were plummeting before it switched to free market economy, the soviet economic model was not sustainable and was going to end up failing no matter what. That's why it collapse and that's why they switched to free-market economy. Except it was too late and their free market wasn't actually free (mostly ended up in the hand of connected former communist member).Russia's standard of life plummeted after the turn to free-market economy.
China is currently on the path to become a superpower(if it isn't there yet.)
I think you picked bad examples.
China is still a pretty poor country, GDP per person is poor by western standard (about half what most do). If you were to split up China into many smaller nation with population similar to most western country, one or two of them would be prosperous (east coast, which are heavily reliant on private industry) and most would be very poor and unremarkable. Another way to look at it would be to multiply America population by 4 so that it would be similar to China and see how weak China actually look like compare to another country of its population size. If China had followed the path that japan or south korea had done after WW2, they'd be far richer today.