What you're describing is an instance of the knowledge problem or the economic calculation problem. Centralism (to which communism belongs) is good at many things -- including huge endeavours such as space travel or going to all-out war. The immense power unleashed during the two world wars was a major inspiration for centralism in the following decades, in the shape of trying to apply this power towards societal good, rather than destruction.

It even worked, in some form, for a bit. Millions of people were homeless or living in very poor conditions, they were relatively quickly re-housed in housing estates build on an unprecedented scale and with unprecedented speed.

But it didn't work at scale. While certainly better than not having anywhere to live at all, many of the housing estates were awful places, they simply weren't built to live in, they were almost militaristic "machines for living in" rather than "homes".

Which brings us back to the knowledge problem: All-out war has the ability to align almost everybody's interest in the same direction - crush the germans. Individual happiness, even liberty, is basically optional, because if you don't win the war, you will have neither happiness or liberty. With this knowledge, it's reasonably easy to organise the economy both on both the micro and macro levels: I need to mine ore for steel for tanks. I need to grow cabbage because we can't import food and cabbage has the highest calories-output per input (taste is not a factor). At every level, you can get a very reasonable approximation of the right course of action by consulting a very small set of shared objectives.

But in peace-time, things start falling apart. You no longer as a society have a short list of shared objectives, the best you can do is something vague like 'maximising happiness' (and even that is debatable). Even if you could identify a big, shared goal, and you might achieve it by suspending liberty, loosing their liberty will make people unhappy and so the means ends up mattering more than the ends (see: war on drugs).

How do you figure out whether growing cabbage or wheat or carrots or raising beef-cattle in such conditions? Different people prefers different kinds of houses, so do you farm trees for wood, mine coal and dig clay for bricks or whatever it is you do to make concrete? In both cases, you need some combination of all, depending on an extremely complex, inherently unknowable, continuously shifting combination of desires in the population -- and the formation of prices in a free market is perhaps not the best (for some value of 'best'), but it's the only known actually functional mechanism to communicate these desires.

Anyway, bottom line: I don't agree that centralised economic systems can even give people better horses, or better cars. If the need is clear and broad enough, it can give people a horse or a car, but it doesn't implement the feedback mechanisms required to continuously incrementally improve it outputs (cutely captured in this meme: http://9gag.com/gag/4298226).