> full screening a single app is a waste of valuable space

Any space not used for the task I'm focused on is wasted. For me the actual problem is that switching apps/windows is too slow because of UI animations.

I run 27" 4k and a 34" ultra wide monitors on my desktops, and my main laptop is a P16S with a 16" 3840x2400 OLED typically docked to one of those screens when not on the go, and I almost never use windows that are not snapped to fullscreen or at the very least to halves or quarters. "Large enough" scarcely applies to a MacBook Air or Neo with a 13" display, and I bet a TON of those get docked to cheap 21, 24, and 27" 1080p screens.

I'd like to be able to snap things to the middle third, especially on the ultrawides.

Only little calculator widgets, property panels, and modal dialogs that get immediately closed after use don't get maximized or at least docked to fill some region. I hate the cluttered, layered feeling of having a bunch of non-full-screen windows overlapping, I want to have a dozen apps open and making optimal use of the available display area.

writing this reply on a 13 inch macbook air...