I don't know much about Epstein specifically, but the way these things usually shake out (you see it in cults, gangs, fraternities, governments, gentlemen's clubs) is that a huge part of the network's job is to make you an accomplice. The coke guy and the trafficker and the hit man can all trust each other because they're all guilty. They all have something on each other and that keeps them safe. It's a safety net that doesn't bind just dealers but also customers; you can't be trusted, you won't be told anything, you won't become friends with anyone, until you indulge. Until you take the bribe or organise a hit or get drunk and go to bed with that fifteen year old girl, come on everyone does it, she's definitely flirting with you... and now you're in, you're damned with everyone else, so there's no risk in staying and so, so much risk in leaving, in becoming an annoyance to so many powerful and clearly immoral people. And you do want to be here, right? You haven't been having fun with us lately; you're not getting cold feet, not going to betray us, right? Of course not. Let's go out and have some fun together, since we're all still friends. Here, take this one on the house. Now I've done you some favours, I've got a favour to ask of you...
It's an old, old pattern. The well-off schoolboys bond by taking photos of each other having sex with a dead pig; the promising cultist gets invited out to dinner with the leader who casually pays for both of their meals with donation money that was supposed to go to charity; the wealthy businessman gets invited to the island.