EDIT: Looking at the screens again..it seems like the CA is more apparent to the sides for some reason
That's typically how chormatic aberration actually manifests due to the shape of lens elements. The center of a lens is typically the sharpest photographically, and the closer to the edge you get the softer the image, and thereby more separation of colors occurs.
Is there any technical reason why you would want to add CA to a game? The only reasonable (and stupid) thing I can think of is that the IQ-degrading element of the technique would somehow free up resources and improve the overall performance, but since I actually do assume CA uses some processing power, I can't think of any logical reason to include it in a game.
Someone, please enlighten me.
Chormatic aberration is simply the separation of colors due to the way light moves through something, so it's most commonly seen in lenses since that's all about how light moves through the different lens elements and thicknesses of glass at the center vs around the edge, etc. But color separation can also be caused for other reasons, like passing through water.
Crysis used it when looking through water to mimic how light actually behaves when passing through it, for example.
Driveclub uses a similar effect for the way light bounces off specific types of headlights.
It can be employed as a specific special effect, like was mentioned
for Titanfall. Other games have similar use cases where the HUD/UI is electronic, and when you get injured or electronically jammed
chromatic aberration becomes prominent for a moment. Or Outlast, where in the game your character has a video camera that you can look through at any time to zoom in, "record" elements for your notes, or activate night vision.
Chromatic aberration is present when looking through your crappy video camera.
Even The Order has a specific artistic reason for utilizing what is maybe the most subtle and realistic recent example of the effect, as they are specifically trying to make the game look as close to a movie as possible, going to great pains to mimic how the image would look through a film camera as far as depth of field, color/contrast, film grain, etc.
But many games seem to use the effect thrown over the entire image just because it's available, without thought into what the use of it actually communicates or without any real justification or subtlety in its use.