These hearings are dealing with legal issues that have already been determined. The only reason Cannon, a Trump appointee, is holding them is to make sure she slow-walks this case past Election Day. Trump's only hope is to win the presidency and then close Smith's investigation, so delaying is the name of his game.
In its eagerness to prosecute the president's main political rival, the Biden administration may have flouted some laws. That's why every hearing Cannon holds is crucial for making sure the rule of law is upheld. Many of these legal issues, including whether Smith's appointment was constitutional, have never been tested in court before and must be adjudicated.
There's a 50% chance that Trump will be sentenced to at least 10.8 months of imprisonment if he's convicted in the classified documents case, according to the Metaculus prediction community.