can't figure out how closed toe bindings are supposed to be better than open

Please help me understand. Almost all pros wear closed toe bindings, so that would seem to imply that they are somehow better than open toe. But for the life of me I cannot figure out how. I am trying to move from open toe to closed toe bindings, but so far I have been very unhappy with the experience.

I am attaching some nice little drawings to illustrate what I'm talking about. I tried some LF Harley bindings, and they fit like the picture labeled C1. My big toe hits the end of the boot just barely enough for it to be uncomfortable, but there's acres and acres of space around every other part of the front half of my foot. So I obviously can't move down a size with my foot already uncomfortably hitting the end of the boot, but if I move up to a larger size there will be even more space. I don't have the opportunity to try the next size larger Harleys unfortunately, but I imagine the best case scenario would be like what I have drawn under the label C2. The area around the front part of my foot would be completely open, but the best I could hope for would be that the laces might extend a little further down the front of my foot allowing me to tighten down on the top of my foot a little further down. But how is that any better at all than open toe bindings? See picture O1 for how open toe bindings fight tightly along the top of the foot all the way down to the toes if you get the right size.

I have also tried some Ronix Ones, since everyone says they are supposedly the best. I have almost the same experience with them. With the size 9s my big toe touches the end, though not quite as uncomfortably as with the Harleys (the Ones feel like they have a bit more padding in the toe), but there's still open space above the front part of my foot and toes. With the size 10s, there's space everywhere around the front half of my foot...which doesn't seem any better than an open toe binding.

So are closed toe bindings a total scam? What is the actual point? Is it to keep your foot from sliding forward in which case you actually want closed toe bindings where your toe touches or almost touches the end? Or is the point to have something over the top of your toes so that when you lift up on your toes it pushes up on the binding and consequently the board in which case maybe you want larger bindings where the laces extend a little further forward down the foot? In either case, a good pair of correctly sized open toe bindings seem to perform equally as well if not better in my experience.

Do I just have alien feet?