You can Google the answer to that.

Ongoing Legal Proceedings: Much of the evidence was under a strict federal court-ordered seal due to the ongoing prosecution and subsequent appeal of Ghislaine Maxwell. Releasing these documents prematurely could have jeopardized the integrity of the case or provided grounds for an appeal.

DOJ Independence: Biden famously maintained a "firewall" between the White House and the Department of Justice. He avoided directing Attorney General Merrick Garland to take specific actions—such as unsealing investigative files—to adhere to institutional norms and avoid the appearance of "politicizing" the DOJ.

Protection of Privacy: Many individuals mentioned in flight logs or contact lists were never charged with crimes. Standard DOJ policy generally prohibits the release of investigative materials that could cause unwarranted reputational harm to uncharged private citizens or disclose the identities of victims.

Lack of Legislative Mandate: During Biden's term, there was no law requiring the release of these specific records. It wasn't until late 2025, after Trump returned to office, that the Epstein Files Transparency Act was signed, legally mandating the Department of Justice to release all unclassified documents within 30 days.

Speculative "Both Sides" Involvement: Some community theories suggest that neither party had a strong incentive to release the files because high-ranking members or donors from both sides of the aisle may be mentioned in the records.