Diamond Stitching

Dear users, dear authors,
what is diamond quilting?

I saw that in the description of a men’s jacket. It was an online store for men’s clothing. 

You can find diamond quilting on upholstery, blankets, jackets, etc. In this technique, the fabric is quilted in a checkered pattern. 

OK. What’s the point of it? Is it just decorative, or does it offer any benefits?

It certainly looks very decorative, but I can’t imagine that’s the only purpose behind it.
Presumably, it’s also to prevent the filling from shifting around too much inside the garment/pillow/… and to help the item retain its shape. This way, the different layers of fabric are held together :)