The Justice Department says Attorney General Merrick Garland will not be prosecuted for contempt of Congress after refusing to turn over audio of President Joe Biden’s interview in his classified documents case because his actions “did not constitute a crime.”
It’s more that after your term is over, you still have protection against having to answer for official acts during your term when you were still president. They’ve gone after Trump for the classified documents because that was not part of his official acts, so Biden has nothing to proect.