and let's be honest - they never achieved communism or even necessarily a particularly advanced stage of socialism. but the USSR in the 60s and 70s did provide a high standard of living to its working class. better in many ways than the US did to its at the time, despite the US being much wealthier (and of course the condition of the working class in the US has deteriorated dramatically since then).

to look to the present day, Cuba isn't close to perfect either, and they don't claim to be, but if the whole world were like Cuba we would be a lot better off than we are today. that would be a world order with a plausible trajectory toward communism.