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.
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?
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.