You could base a society on randomly selecting people at a young age to be elite. It would still have advantages over a society with no elites at all. The goal

You could base a society on randomly selecting people at a young age to be elite. It would still have advantages over a society with no elites at all. The goal of having an elite class is to make better collective decisions about how society should organize itself. Decisions are best made by people with the best information, and elites (regardless of any intrinsic merit) have better information. By virtue of being elite, they get better educations and more inside access to new information. The classical way of doing this was through inherited privilege. Whatever intrinsic merit first-generation aristocrats may have had to win their position is mostly gone after a few generations, so for example 19th century English aristocrats had little genetic advantage over the average population. But they were selected at birth to receive the best educations and inside access to each other, so they made better decisions than if you chose random citizens in adulthood to put in charge. Part of what Harvard does is to say "You are now an elite. You will shape the future of society." Most students take that seriously and try to become worthy of the challenge. No society has tried selecting random people in adulthood to put in charge. The closest natural experiment is societies that select leaders based on physical strength and courage. They seem to make fairly bad decisions.