The USSR lasted for less then 70 years. During that same period of time it lost a large number of its people in ww2 and millions more from its own methods. I really don’t think you want to be using the USSR as your measure of successful socialism. It at best shows socialism has less long term stability then say capitalism. We may find that capitalism has a limit but in the modern era it’s still got examples that are going quite strong. You are blaming the failures on a quick transition but at best all I’m seeing from what you’ve said is that a quick transition causes socialism to fail faster. You didn’t point out any examples of socialism to capitalism causing the same failure. The answer can simply be that there’s been a complete lack of cases where that’s even happened but that still means there’s not evidence of your claim that doing it either too fast will result in failure.

I rather like your post. It’s something different from what I’m used to seeing.

TLDR- I just don’t think the evidence you presented so far backs up your claim. I’m not discounting it. So far I’m just not seeing enough to make me agree with you.