World historical geniuses have all-but disappeared from Western civilization - that is is simply a factual observation.
Either we can consider the disappearance due to a decline in intelligence and or creativity and or motivation; or we can consider that the deity has withdrawn genius from the West (because we have so often corrupted and misused it); or both.
But what could we, what should we, do about it?
The problem is that the problems of Western civilization are large, yet we have not enough geniuses to solve them (or else the geniuses are still there; but now unknown, un-empowered, ignored and/or suppressed).
In other words: the problems are significant and multiple, the problems need to be solved - but they cannot be solved at a large scale because we lack the people to do it.
Therefore it seems that the problems can only be solved partially, for instance, melioration and damage limitation rather than cure; or genuine solutions but only on a local and restricted scale.
In a major-genius-free world, then those who are put forward (hyped and trumpeted), or put themselves forward, as world historical geniuses will be fakes of one sort or another.
The lesson may be analogous or akin to the Small is Beautiful, or 'intermediate technology' message of EF Schumacher: awareness of the need for a smaller scale, a more human scale: more local, more understandable... a preference for the partial and piecemeal.
And a rejection of gigantism and always-growing institutions; the massiveness of media; the world of master narratives, international panaceas, globalization of attitudes; the winner-take-all economy of cash, fame and kudos; and the strategic interconnection, interdependence and mutual subordination of everything.
In a world without genius; either we cultivate our gardens, or else nobody will cultivate any gardens; hence gardens will not be cultivated.