Okay, so this may sound nooby but... how do i remove the Cravers from the galaxy WITHOUT colonising all their crappy depleted systems? Before i just evacuated the systems and never returend but i'm seeking an easier and less time consuming option. Pls help. Thanks.

The quickest way to remove Cravers from a game is to not start a game with Cravers in it.

Seriously.

The Cravers' playstyle is centered around the idea of a viral "snatch-and-burn". Left unchecked, you will have a lot of depleted systems to conquer to remove them from the game. Right now there's no way to stop that from happening (aside from stalling and containing them long enough to exhaust their ability to build back up).

There should be planetary revival tech we could use to un-deplete systems. But that just removes the threat the Cravers bring into the game. Their most dangerous trait is not in their manic expansion - it's the ashes they leave behind that everyone else has to deal with for the rest of the game.