$500K as a software engineer? That's the very tip of the unicorn's horn. My friend works as a CEO of a (smallish) software company and makes half that.
This forum almost certainly skews heavily towards people in Silicon Valley or working at Bay Area companies. AKA the very highest earning people in tech.
It's the difference in working at a public company that offers RSUs and bonuses vs working for a startup. Your base salary will be somewhat similar, but startups can't compete on total compensation.