Also this.
My guess as to what's in the Epstein files is a lot of shit implicating some people who are dead or are so old they might as well be dead in crimes, and embarrassing many more who were friends with Epstein and very likely knew he was a pedo but didn't care, and both of those groups of people were/are wealthy and connected people so I'm sure there's plenty of people on both sides of the political aisle who would prefer they not be released because their associations with them would be embarrassing. There's probably also a lot of evidence of overseas financial transactions with Epstein's foreign collaborators that the DOJ didn't really care enough to chase down once Epstein killed himself, especially after they had to pivot to focus on prosecuting 1/6 assholes.
Garland and most of Biden's administration thought Trump would slink away quietly after he lost (this is well documented and I'm not going to re-litigate this if anyone has the urge to argue), their norms and rules didn't permit releasing the Epstein files, and they would've been concerned about the impact releasing the files could've had on their own friends and associates. I could even believe that they were never even consciously thinking about potential impact on friends and associates, and just were being "good" little rules followers, because that's who Merrick Garland is and that's who most mainstream Democratic public officials are, especially those who are lawyers. I don't believe that, I expect there were at least some people high up on Biden's DOJ who were worried about that, but that wasn't even necessary for Biden's DOJ not to release the files.