See, earlier: Is the Mar-A-Lago Whoop-Tee-Doo About...Memorabilia?
From the New York Times news section, by Maggie Haberman, the political reporter who knows Trump best:
As with so much else with the former president, there is not one easy answer as to why he refused and ignited a legal firestorm. But here are some possibilities.
Former President Donald J. Trump, who for decades showed off knickknacks in his overstuffed Trump Tower office, treated the nation’s secrets as similar trinkets to brandish.
By Maggie Haberman
Aug. 18, 2022, 5:00 a.m. ET
… Exciting documents
Mr. Trump, a pack rat who for decades showed off knickknacks in his overstuffed Trump Tower office — including a giant shoe that once belonged to the basketball player Shaquille O’Neal — treated the nation’s secrets as similar trinkets to brandish. White House aides described how excited he was to show off all the material he had access to, including letters from the North Korean leader Kim Jong-un, which he routinely waved at visitors, alarming his advisers.
Some of those letters were among the trove that Mr. Trump had with him at Mar-a-Lago.
This would explain the insistence on hanging on to physical rather than digital copies: they’re memorabilia to hang on the wall.