The entire world has adopted capitalism. Because innovation, adaptation, production, distribution and trade are not possible without it.
The current argument is that low trust, traditional-family, and tribal-family polities, particularly those that practice cousin-marriage, cannot operate without a dominant state, and that high trust, absolute nuclear families are uniquely able to operate without a dominant state – relying entirely on common law. And that the unique circumstances that allowed northern europeans to develop the high trust society cannot be repeated without returning to manorial era suppression of the reproduction of the underclasses. And certainly cannot survive the immigration of new castes of underclasses.
So when we refer to peak capitalism we refer to the expansion of the world’s low trust demographic distribution evolving into the majority – both in absolute numbers, and in aggregate economic and political influence.
Capitalist meritocracy is only tolerable to the upper classes. When europeans were the worlds dominant upper class, others tried to imitate it. Now that we have been displaced through reproduction and immigration, that meritocracy is no longer advantageous to the remainder of the planet.
That is the most honest, probably most scientific, and most probably answer to the question.