When a drywall crack returns, the original repair probably treated the line but not the cause. Cracks can come from framing movement, weak tape, corner stress, moisture history, or a patch that did not bridge the damaged area correctly.
A narrow swipe of compound over a crack may look fine for a short time. Once the wall moves again, that same line opens back up. The stronger repair is to remove loose material, reinforce the joint, and float the area wider.
Corners and ceiling lines need special attention because they carry more movement. If the existing tape has failed, new compound on top of it will not perform well. The loose tape has to be addressed.
Texture and sanding matter after the crack is stabilized. A repair can be structurally better and still look obvious if it is not feathered into the surrounding plane.
The goal is to stop the crack from telegraphing through the finish and leave a paint-ready surface that does not announce the repair.