"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.

I can't speak for anyone else, but when I use "best society" it is code for the following argument that gets as long and involved as there is time to explain:

Human instincts and morals are really well calibrated to small-village life. I take things like the Dunbar number [1] to indicate that we are optimised for a small circle of close relationships.

"Fairness" has a sister in "equality" that is very powerful force on the local scale and scales horribly, to the point where equality being scaled up is usually a warning sign of an incoming economic breakdown where everyone starves. Unfortunately, people keep trying to scale equality up because they want it in their local relationships.

Talking about "permanent power disparities" touches on the same vein of thinking - we know that permanent power disparities are an inevitable feature of society. The attempts to set up societies where there are no permanent power disparities have resulted in permanent power disparities forming, and frequently going to very nasty despots. Modern western civilisation has done _extremely_ well compared to the competition by dangling systemic advantage as the reward for massively improving the industrial base and consumer access to resources. This has worked a lot better than attempts to suppress inequality under, eg, the communist systems.

[1] https://en.wikipedia.org/wiki/Dunbar%27s_number

I don't see what fairness and equality have to do with one another. Consider a poor person and a rich person. The poor person gives $100 to charity and the rich person gives nothing. They're not economic equals, but which would be more fair? A tax deduction for the poor guy or the rich guy? Extrapolate.