Anecdotally, I see some people in their 40s or early 50s who made very serious money and worked really hard (founders, CEOs, and the like) end up doing some of the on-the-side type of work that gets thrown at people in that position (boards, "advisors," and the like). But I don't actually see a huge number of late career regular employees (even fairly well-compensated ones) retiring way early.