You can't release files if cases are ongoing for a number of reasons. You don't want to compromise the ongoing cases, victims need protected, etc. There are also various legal hurdles, both state and federal- that protect grand jury testimony, for instance.
Also, the President doesn't get to unilaterally decide to release files.
Any reasonable person would want to expose child sex traffickers, rapists, pedophiles and their associates.
There certainly were ongoing cases during the Biden administration. From what I can find, the only ongoing legal matter related to those files is the Maxwell appeal to the Supreme Court.
I don't want the DOJ to compromise cases against these a-holes, but I would like all of the affiliated people exposed as soon as the last case related to those files is finished.
This is only a political matter because there are sure to be politicians involved on some level. All of them should face the consequences of their actions. ALL OF THEM.