I have expressed my views on this before, but I guess I need to again.
Communism does not work with current models of human being; Or at the very least, not in aggregate.
People want to stand out. They don't want to be ordinary, they *ALL* (statistically at least) want to be trend setters, movers, shakers. This is of course, impossible, but you only need to look at how social media works to see this in action. People post like they are all famous movie stars, with adoring fans. There's a metric (Number of followers) for success at this even, and a drive to reach the highest values for that metric. Such "Popularity" has been a fixture of human social dynamics since before the stone age. It's part of our baseline behavioral programming set.
This maximization of a socially defined set of metrics, and damn the consequences, is basically the same set of things that drive predatory capitalism. In that paradigm, instead of "Followers", it's "Size of holdings." How rich you are determines your standing in the hierarchy, and your ability to set and enforce your views onto others through the power that position gives.
We are hard wired to seek out, graduate into, and perpetuate these kinds of social hierarchies.
Communism runs into a wall with this.
"Each according to his need, each according to his ability."
What does that actually MEAN, and why does it run counter to this natural state program humans are running?
Well-- It literally means "Each person receives what they need to live", provided by "Each other person, according to their ability (To provide)" This runs counter to the greedy maximizer software we are all running, because the purpose of that greedy maximizer routine is to accumulate resources FOR OUR OWN USE, not for the use of another who needs it. Certainly not such another person that they do not know, nor have any dealings with, or have any direct tangible benefit from assisting.
"Why should I have to pay for that person's college!?" et al.
It can be explained in brutal levels of detail, but the disconnect between "Look fucker, you benefit by having a well running society in more ways that you can possibly imagine-- If you are able to help grease the wheels of that without undue burden to yourself in the process, you benefit in a diverse and spendid cornucopia of ways by helping random people get the education they need to perform at their highest levels." and "But I could use that money to do something I personally enjoy, and which will make me stand out among my peers! I worked HARD for that money! It's MINE!" is never satisfactorily bridged, especially as the group size becomes thousands, then millions of people-- instead of the few hundred or so humans are wired to be able to keep track of, and fully appreciate the interconnectedness of.
But we need to limit that selfishness-- Otherwise, our societies would destroy our planet (faster than they already are.) We do that with government. Government is really just giving authority and the right to impose physical restriction and punishment to a small, manageable group-- to oversee the greater function of the larger societal structure, and help assure its function. It is literally enabled by authoritarianism, and the implied capacity to use force. (which is what jail actually is.) Current capitalist systems enshrine certain features of the natural selfish programming, which makes it innately appealing on the instinctual level, but this incorporation introduces very undesirable consequences (such as mass disparity in total wealth over time.)
Enter communism.
Communism seeks to eliminate that disparity of wealth, and assure maximal utility of resources by preventing hoarding, down-regulating selfish behavior, and up-regulating pro-social behavior.
The problem--- the only tool to impose that, on an architecturally incompatible psycho-normative population pool, is----- GOVERNMENT. Which is, again, just a systematized and organized use of force to enforce a societal set of norms to assure compliance.
The use of such a system-- government-- is incompatible with the goals of communism, because the government agents have no real restrictions on them to not engage in the "more comfortable" selfish activities. This leads to social stratification of "Party", and "Proletariat", such as in the USSR model. Officials have power that ordinary citizens do not, and they can (and do!) abuse those powers for personal gain, with little to no oversight or consequence. This is completely incompatible with the stated intention of communism.
So-- when I see arguments like "Communism would work, you just cant be authoritarian!", i liken it to "My water bottle rocket would work (to reach orbit), if I just changed the earth's gravitational field strength!" Both are true, and both are meaningless. The former, because it discounts that human baseline behavior is governed to a non-trivial degree by evolution and genetics, and the latter because the earth's gravitational field is defined non-trivially by its mass, which you can't handwave away any easier than the former.
You don't get to the finish line straight from the starting line, without running the course of the racetrack between.
Humanity has to exist at a technological level long enough to meaningfully evolve away from the parameters that produced us initially as hunter gatherers, in order to be able to meaningfully engage in true communism. (OR, we have to artificially accelerate that process with genetic engineering, and incremental adoption of pro-social behavioral norms and customs.)
It really irks me to no end when people profess that we can get there "now!".
No. No we can't. Any attempt at that will quickly end up like China or the USSR. The best we are able to do NOW is what is going on in the EU countries. Progress will be glacially slow, but meaningful.