Rich people regularly are invited to meetup events with other rich people, business is 99% a social relations.

For example, while looking up Salinas Pliego (mexican oligarch, currently engineering a trump-ish movement) i found out he met Epstein at an edge billionaires event organized by some grifter guru, among many other billionaires. Billionaires don't attend these events to hear whatever the guru is saying, they go to meet other billionaires, so imagine a guy like Epstein, someone that made his fortune entirely by sycophancy with wall street investors, meeting other sycophant billionaires.