

Not sure if Biden/dems have given a reason yet. I believe, typically, the official reason they keep this files secret is they may still intend to take legal action in the future.
Unofficially, Biden’s AG Merrick Garland really did not go hard against Trump. They let him get away with an attempted coup, not sure if that was at Biden’s request or if Garland persuaded him not to.
Farfetched theory on my part but Biden really tried not to stir the waters, I feel, to avoid a civil war.

Betrays Ukraine, Europe and their allies