The door lock is a double latch. As it closes, it should click twice, and usually only the second click will allow it to lock. You can see and feelthis on other doors. Your pic looks like a door on the first click only.
If the handle is held 'open' as the door is closed, does the door fit neatly in its aperture?
If it does not, that problem needs addressing first. Worn hinges will allow the door to drop, and the striker does not do a good job trying to lift it as it closes.
If the door closes neatly, without any forced raising or lowering, your pic suggests that the striker on the car pillar is out of adjustment. Its two screws can be slackened, not removed, and this allows the striker to move, in all directions, so the screws need to be just tight enough to hold its position while you adjust it. It is possible that the striker has been pushed too far inwards, causing the door to have to squash the doorseals hard to be able to close. Slamming the door can cause this, do you have a passenger that slams the door?