"Permanent power disparity", "best society" - that's completely orthogonal to meritocracy. You could implement meritocracy (i.e. most skilled people in temporary position of most power) even in a system that has a "reset" every generation (e.g. by eliminating breeding and growing people Matrix-style). Like markets, meritocracy should be used to "optimize" the outcome towards whatever the society deems beneficial - e.g. these days we consider renewable energy beneficial, so policy is guiding markets to force investment into renewable energy (by taxes etc - despite renewable energy not being competitive on its own) - just a simple example of markets adapting to the values of society.

Yes, the current system (Western-style democracy, capitalism, freedom, markets) is the most meritocratic of all systems realised so far (AFAIK), but that doesn't mean we can't do better still.