Unless we don't care if socialist countries last, it matters a great deal whether they can grow (whether that means GDP or material output as Wojtek suggests).
^^^^ CB: This is not to deprecate what you think through in your discussion on this thread, but the critical factor in the first socialisms not lasting longer was the wars perpetrated on them by capitalism not their slow growth relative to that of capitalism. "The final conflict" involves "world revolution", i.e. whole world reovolution; that phrase from Lenin's era is still the ultimate goal. It is also demonstrated to be a necessity by the end of partial world revolution. So, real socialism and communism cannot come into existence until there are there is no more capitalism in the world. Communism is a world system.
Again, the main cause of the demise of the first efforts to build socialism was the world historic level of violence visited and threatened against the socialist countries - Soviet Union, Korea, Viet Nam, China,etc. This caused militarization/sharp hierarchy in the polity and enormous loss of material resources to military production, not to mention the total economic and human destruction of the Nazi war , requiring almost building from scratch the first successes. When Lenin formulated "peaceful coexistence and competition of different social systems" the bourgeoisie knew to do the exact opposite : "make the biggest wars ever on socialism"; and that strategy succeeded.
The key in the next effort to build socialism is to start it in the US , so that there won't be an overpowering, world dominating imperialist state. Easier said than done, but there's no choice given the depths of depravity capitalism and capitalists have demonstrated they are willing to go to crush socialism