

Because you don’t publish details of investigation. You publish indictments once investigation is done. That’s essentially weaponization of DOJ.
Republicans were promising to release (and suggesting Democrats are on it). Now as they have the power, they refuse. Claim the files don’t exist then that they are fake, then they are boring.
At this point it is very clear that trump is in them.
The thing is that you normally don’t release details of pending investigation, but trump and Republicans were riding on this promise and now that they actually have the power they looking for excuses “files don’t exist”, “files were created by Democrats”, “why you even talk about files?”
It is clear that trump doesn’t care about integrity of the investigation (given that people involved in it were fired I think effectively it is stopped) but that he is in those files.