Why is still extra spacing on my pasteboard if all margins from the pasteboard options are removed?

The area marked with the big rectangle on my third image IS the pasteboard.

The pasteboard is useless space while creating, so I don't want it.

I work on a 12.5 inch HD laptop, which suits my eyes cause I (still) have good eyes, and I am on the road, so I don't want to carry a bigger laptop. So i need to spare my space on the screen.

But the main reason why I don't want the pasteboard is that I am resizing the document window to the physical size of my document, because if you do that, you can navigate just by clicking on the pages in the pages tab, while having a perfect physical size view (and no bloat, no extra space, no pasteboard), without scrolling or panning while creating the document, because InDesign it seems it's made smartly so that it will scroll the spread to the max right when clicking to the right page on the spread, and to the max left when clicking on the left (facing pages).

I know that sometimes you need a bit of a pasteboard to paste stuff that you don't want to paste into the pages directly, but for that I can use the pasteboard areas in between the pages, vertically.

I am already set up with the setup mentioned above for my document pages document.

Now I need to set it up for my jacket document.