Going to go long for this one, even if it means it will be skipped. Don't know if I can go short and get any kind of point across other than to say communism would likely fail in an ideal world, and this is not an ideal world.
It is hard to divorce aspects of government from the economy. If the government has no economic levers* to pull then they almost cease to have power and at that point we have anarcho capitalism at worst and laissez faire at best.
As with most things it is also a spectrum, and of many dimensions. Some might even argue communism is not even on the spectrum and is in fact its own thing but I will consider it as an extreme end of socialism for this (this going whether you are following Mao, North Korea, later Chinese efforts, Stalin, Trotsky, Lenin, Marx, heavily revised Marx or the near mythical proto communism efforts which have no texts, historical implementations or really anything to look at or contemplate, and would be made before the industrial revolution, never mind the silicon and networking ones).
As a post scarcity world does not appear to be on the horizon just yet (be it by replicator or VR), and we are also all similarly apes that, biologically speaking, are still only adapted for small tribe (let's go with Dunbar's number) living in a savannah we have to consider that too.
*whether these levers are top down, bottom up, ever even knowable (something in one place can have vastly unexpected effects in vastly different areas**) or something a government should be touching... actually I was going to say is another discussion but realistically it is this one.
**see the recent failure of Archeos
Various companies noted in graphs in those had share prices tank as a result of that. Was it because they did anything wrong? Nope some banks which owned said shares had over extended themselves (in a rather silly manner) and had to sell off, mass sale means prices drop. But one example of unexpected changes in one area causing knock on effects in another.
Communism and economics thereof. Historically has failed everywhere it has been tried at a scale larger than a farm, and even those tend to fail. Generally tends to utterly fail to account for human psychology, how things work, advancement of science, geography (sell ice to an eskimo, sand to an arab and all that, even though amusingly enough there are examples of both -- desert sand is useless for concrete we have today and owing to international shipping codes then ice does indeed go to iceland
https://grapevine.is/news/2016/10/20/imported-ice-cubes-in-iceland-cheaper-than-domestic-ice-cubes/ . Though more generally this country has better farmland, infrastructure already there and oil just waiting to be sucked out of the ground).
The idea of a centralised price model rather than model realised in the field is so utterly moronic that I struggle to even state how much it is, and it is a fundamental aspect of communism from what I can see. Amusingly enough we can happily look to some of the most hardened and ardent supporters of capitalism as the amount of waste and stupidity that happens in government projects, departments and militaries is staggering.
Even without that you have hard problems if you have limited resources. So you whip your workers hard enough (presumably by making the whip masters fat and happy -- Maslow's hierarchy and all that, so much for equality I guess) that you have produced 200 units of steel. I could state a number for demand for this example but frankly it is infinite (if there is some going then drop it in my garden (I*** have 500 acres of it because I guess land is not a scarce resource and there is always more of it), I will find a use for it one day and enjoy it in the meantime), though leaving aside that do I build railways or do I build buildings? Both will benefit but now we get to quantify it which is almost impossible, and that is just for two scenarios for a single resource.
***how one handles the free rider problem, sociopath problem and more is also up for debate. Now at some level cooperation is baked into human biology (it is a rather successful strategy) but there are also those blessed few born without such qualms or raised such that they are similarly unbothered, and being that in a society of sheep is potentially quite lucrative. Master your baser urges, and also be given some boons and all of a sudden you have the work ethic, smarts, fearlessness (checking for the lion behind the bush is useful but the one that carries on running without checking is the first to spear the gazelle, except there are no lions any more and the ability to take risks will get you ahead).
Of course free riders and sociopaths are one aspect. Price's law
https://dariusforoux.com/prices-law/ (50% of the work is done by the square root of the total number of people who participate in the work) kicks into play too.
At the same time I have spent a lot of time in the US. Not a shining example of things there -- only time I have ever heard a medical issue leading to bankruptcy here in the UK is a company going pop because one of their key employees lost a game of beat the bus and while everybody is replaceable at some level then some are harder than others (another thing to consider -- everybody is not equal, some are stronger, smarter, more resilient, less sickly... and that is played to by both nature and nurture and the idea of a blank slate is also ridiculous, all this before you consider the biological and psychological differences between the sexes).
The nature of fines and laws and the almost adversarial nature of things in the US... no thanks, though I can just about deal with it (me being a skilled person without any debts or responsibilities that is familiar with general legal procedure, has training to resist psychological pressures and the ability to drum up a fair bit of cash in fairly short order almost regardless of my social standing). Can do happily and far more easily in much of Europe though, especially once you get outside the capital cities (though how much said cities are dragging the rest along with them is up for debate).
The US' take on town planning, house design and more is abysmal,
the strong towns series by not just bikes serving as a pretty good primer here and that is a nice centrally planned/dictated setup (what is a zoning law if not...). Not that places like Australia, Japan, the UK or much of Europe do better in every regard.
On Europe though then also a developed part of the world, nice weather... basically comparable to the US in most ways that matter for people, how smart said people are and the rest. Rather different number of tech companies (name me even 5 that are going toe to toe with any of the US efforts, and those that do rise up usually get snapped up and happily move to the US) that push things forward.
Equality of outcome is boring, and everything in psychology says humans are hierarchical and tribal. You compare yourself to your immediate peers most of the time (why those earning a lot more than you or I might still steal). Hardship is also a thing to face -- how many companies don't make a fourth generation, how many trust fund kiddies fail hard, how many people on benefits are basically sheep...
Amusingly enough for all those that might say we never had proper/true communism (something I would say is an impossibility pending without post scarcity or radical changes to biology) then I don't think pure capitalism has ever been tried (be it anarcho capitalism or laissez faire flavours) and certainly not in the modern world. The US for example has any number of things from medical care (see percentage of GDP spent on things, more than border force military, police, fire, libraries and much more besides, as well as any number of interesting incentives and caps on things).
To that end. Some flavour of mixed economy works for me. Prefer the various models of northern Europe to most places, but they are also not without problems. If you wind in politics then I would probably skew even further away from communism as historical abuses (which seem inevitable) there are far more unpleasant than having to deal with some nepotism.
