Even though the answer may be obvious to some people I'll ask it anyway:
Why did communism fail so spectacularly?
Like it's often said, on paper it looks wonderful, but it's horrible on practice.
So what's the problem in it?
Is it really "real communism has never been tried!" or is it rotten to the core?
[spoiler]it started with Kruschev though, revisionism destroyed the movement and the nations of socialist construction, which also failed to update technologically and wean the proletarian economy off of just Party overwatchers and also failed to make Party members actual experts and activists[/spoiler]
1. Communism was never "tried", it's a pipe dream, a fairy land fantasy
2. Communism is arguably not even a utopia
3. A class-less society is an oxymoron.
4. The CCCP didn't follow Marx's ideals, but used him as a mascot.
5. The CCCP was much like other states of the time, just more subvertive and buerocratic
6. Your thread is shit
Empathy. You can only know and care about several hundred people at most. Anyone outside that sphere? A total stranger you don't give a shit about. So when you're stealing from the community, you're stealing from a community of mostly people you don't give a shit about, and it doesn't "really" hurt anyone you know, so it's totally okay.
In that sense it's like democracy except even more dependent on the community size: Works great in the scale of a village, not so great once there are thousands of people involved, and doesn't work as advertised at all when you reach tens or hundreds of millions of people.
I think in some part it had to do with the fact that the west was able to lever in things like entrepreneurial freedom to advance their economies/technology in ways that the USSR couldn't keep up. By the mid 80's, the difference in computing power for the average user would have been massive.
Furthermore the western capitalistic system prioritized growth and development, while the USSR was slow to use its natural resources on the global market.
Look for example at China, which managed to realize that communism cant work without (das) capital ( :^) ) and pivoted their economy towards a semi-capitalistic model in order to facilitate the growth necessary to maintain stability in a non-democratic system of government.
communism was never supposed to be done under these conditions. It's a shame, because in a few decades we'll stand with almost infinite resources and communism would be great, but there's no way we can go that path again now.
No, even if we reach the technology allowing us to launch into post scarcity, the resources will still be kept artificially scarce. That's just because finding a competitive advantage is human nature.