In this new world we may need to accept that our individualistic nature has become that very same weakness that dooms our way of life in the great game of life.
What is the its you are referring to when you say technology hampered its effectiveness.
Secondly, I don't believe it is widely accepted that our nature is individualistic. Individualism is a moral stance, political philosophy, ideology, social outlook.
However, in the age of instant global communications, it may be that effective central planning is "better," or at least possible.
And now, the individualistic model may not be compatible with the planet-scale adjustments we need to make to prevent catastrophic environmental change.
Also, I agree individualism is not necessarily humans' natural state. We probably self-organize into loosely affiliated extended family units in the absence of imposed hierarchy, but humans are nothing if not adaptable.
Italy was something of model for alleged central planning efficiency in the last century. Now it's broke, taking money from the next credit-binging central planning state. It's credit, not proof of either side having superior economic policy.
And I will add one more thing other than instant global communication. Big Data. You can now have Data Real Time and see the Trend and changes being plotted in real time as well.
I also don't know what is the difference between Central Planning and Keynesian.
The truth is that humans are social creatures that prefer the company and support of other humans. The way we spread around the globe as hunter gatherers was through cooperation and mutual support. A lone wolf cannot support themselves if they are hurt, or sick, or lack a skill, or simply didn’t save enough food in hard times. But a community can.
So, I don’t think our nature is individualistic so much as capitalism is individualistic.
However, centralized planning has one fatal evolutionary flaw -- any errors from the top are amplified. The biggest example of this was China closing its ports in the 1400s following imperial decree, which started China's long path to civilizational decline because it cut off trade and new ideas. (China's thinking was: we're big and diverse enough internally -- we don't need no one else. This kind of insularity always brings about downfall.)
In Europe, because there wasn't a single monolithic power but instead many independent jurisdictions, as a whole it was more robust to errors. When a certain nation-state was on the rise, another declined, but overall there was progress. There were many golden ages, e.g. Portuguese, Spanish, Dutch and English, and they each had their time in the sun. Europe as a whole progressed.
Centralized planning is always more efficient; but if the leaders get it wrong, errors can be catastrophic.
Decentralized/democratic systems are always less efficient; but are ultimately more robust to changing environments and errors in the system. They are self-correcting to some extent.
Many successful countries start out with centralized systems, and often transition to decentralized/democratic systems (often not without some upheaval). The United States (and a few other countries) are unique in the sense that they started with a democratic ideal, but as far as I can tell they are exceptions to the norm.
But such a thing would probably require forming a new society from scratch. As you mentioned, the USA was the "Great Experiment" that many old-world royalists scoffed at. Maybe the time will come for another?
The biggest problem is people who insist one of those stances is the only correct one in practice, as well as morally, and deride other proven better options simply because of an ideological distaste for it.
A lot of us here are from the Tech and specifically software industry, and one of the most common refrains is to use the best tool for the circumstances. Sometimes that may be a functional language like Haskell, and in other cases may be Javascript.
The same concept applies to central planning vs markets. Both are just a few of many tools, and the correct approach is to pick the best tool for the specific job.
First social creatures that "discovered" hierarchies were lobsters about 300 milion years ago. This is before even trees existed. Very long time from the evolutionary perspective, i.e. they do provide advantage to species that employ it.