Epstein was able to get off easy and got such an incredible deal because of something extremely obvious- a lot of powerful people like Donald Trump, Bill Clinton, Prince Andrew (of whom there are literally pictures of him with one of the underage victims) were his friends and would be implicated in child prostitution if Epstein gave them up to reduce his sentence. Plea deals generally are about reducing your sentence to implicate other inspaniduals who committed the crime, this one is about protecting them. One of the things that makes this the most obvious is that the fucking deal that was made gave immunity to "any potential co-conspirators", meaning that not only does Epstein get a slap on the wrist, none of his buddies who fucked kids on his island can ever be tried for it. Epstein was literally allowed to have a mistress who Epstein described as his "sex slave" that visited him in jail 67 times. He was allowed to leave jail all the time. He was housed in a private wing of the jail. This is not a man being punished, this is a man being protected. The Trump presidency is honestly more likely to get taken down by the Epstein case than by Russian collusion. There are at least two girls that have accused Donald Trump of raping them at Epstein's home by name.
It is a common thing among people involved in organized crime to make sure that everybody gets their hands dirty so that everyone has a shared interest in none of them getting taken down. That is what is clearly happening with this child sex ring and the powerful people involved in protecting everyone involved.