Mainly, I made the target out of my own personal preferences so the target is pretty beneficial for my purposes. I personally find the traditional large circle targets sort of limiting and kind of boring and out of the dozens of targets I've downloaded and used I always preferred to make my own.
Squares: The squares give me multiple defined aiming points vs a circle target. The smaller inner square works well with my higher mag optics while the bold outer square provides good visibility when zeroing my LPVO. Five of them let me do a 5X5 target to gauge the average accuracy of the rifle and ammunition. The gray provides contrast for LPVO use and helps me see impacts better at 100 yards vs. a blacked out box when using the riflescope vs. a spotting scope, which I don't have.
Squares Layout: Having a 2 mrad X 1 mrad layout allows me to confirm the subtensions on my optics, specifically the SFP ones. The distance to the target needs to be precise but it can allow me to confirm that on 10X for example 1 mil equals 1 mil and find the true half power. When I need more field of view I know where along the magnification ring I need to turn to hit true 5X so the reticle can be somewhat accurate still, my holds are just 1/2.
Diamonds: The diamonds can provide additional defined aiming points when using a magnified optic. At 50 yards the diamond over the C-Zone torso gives good contrast to make it easy to see when using my iron sights or red dot. The black diamonds give secondary points of aim for confirming zero.
C-Zone Target: At 100 yards, this is the target for my piggybacked red dot. Put the dot center mass and let it eat. It being scaled 1/3 size means that it can also be pretty versatile for practicing positional shooting or sling shooting with multiple rifles. For example, at 25 yards it would make a pretty good target for my Appleseed rifle to practice offhand, kneeling, and sitting positions.
For me, and again, I designed the target for me and my shooting preferences, it works to combine several targets I'd been using into one.