Trump was hoarding documents for four years and nobody said or did anything about it.

[kentuck]

Did they really think he was going to turn them over to the National Archives on his last day?

Several people had to know he was taking the documents and not returning them. The White House Counsel, Pat Cipollone, must have surely known. So would have the Archivist that kept a record of all the files that were checked out and went to the Oval Office. Also, the Chief of Staff would likely have known.

One would think that John Kelly and Bill Barr, in their previous positions, would also have known, as would have any previous Chiefs of Staff and the people that checked out the documents.

With the empty folders that were marked to be returned to Staff Secretary/Military Aide, someone would have known if they had not been returned, one would think?

There are a lot of players in this espionage plot, willing or unwilling, that have not yet been identified, in my opinion.