Part of the way it survives is by setting up the system so that just enough people survive the gauntlet of meritocracy. They're held up as demonstration examples. Pointing out 16 self-made billionaires, for example, leads people to think it's common enough that it might happen for them, too.

An additional twist is that some of those who make it are the ones helping extant powers maintain their grip. WhatsApp and Oracle come to mind.