I guess he wants to nail down his legacy as Most Corrupt President Ever, since, as far as I know, none of the people he pardoned face federal charges, and he can't pardon state charges, like the ones Guiliani is facing in Georgia. Does it make him feel like he might get into heaven? God knows, Tipplin' Rudy has made himself a ruined man in service of his King.

More likely, Trump wants his former "allies" to keep quiet. Via the NYTimes:

President Trump has granted pre-emptive pardons to Rudolph W. Giuliani and others accused of trying to overturn the results of the 2020 presidential election, according to an official familiar with the matter.

The official, who requested anonymity because of the sensitivity of the issue, said on Monday that those pardoned include John Eastman, a lawyer who advised Mr. Trump’s 2020 campaign, and Sidney Powell, a conservative pundit who was briefly a public face of his campaign.

The presidential pardons, which would only apply in federal court, are largely symbolic. None of those named are currently facing federal charges, and the pardons cannot shield them from ongoing state-level prosecutions.

Maybe it's meant to reassure the minions he's currently using not to worry, he'll take care of them.

Here's a partial list: