Arguably "success" is an externally managed and unbiased shorthand for quality.

As in, it's hard to "get ahead" by definition. So anyone that's overtly ahead of the pack has therefore been vetted as superior to most everyone else. It's a reasonable proxy for gauging intelligence, charisma, and interpersonal skills without even meeting them.

As you get more information you'd realize he made his millions making, say, a software product so, fine, that lowers the assumption of interpersonal skills and charisma and increases it of intelligence. Regardless, the shorthand implies an excess compared to average.

TL;DR - Arguably, "successful" is a rational and effective way to gauge a mate's value.