It might've been, but I agree with the core point: make window tiling an option. For the amount of time that it would take to implement, and the non-zero number of people that would benefit from it, it seems a glaring omission. Every OS should let you line up two windows side-by-side out of the box: this should be a minimum requirement of any window manager that lets you have windows at all.

Full screen mode is macOS native tiling mode, you can put two windows side by side and use as much real estate as possible (no menu bar nor title bars)

Eh, that’s pretty darned far from an i3 or Xmonad experience. It’s roughly as wrong as saying that the Gnome frameworks are just as good as Cocoa :-)

I have used i3, awesomewm and Xmonad extensively for years so rest assured I wasn't implying anything like that ;)

I was more like pointing out that macOS does allow for the following in some way out of the box:

> Every OS should let you line up two windows side-by-side out of the box

Sorry, that really was only an example. I also didn’t say, or mean to imply, full-screen only. Every os should also let you line up windows top-to-bottom out of the box. Etc. Macos' approach of allowing one very specific combination of window arrangement, then trying to make a feature of it by calling it 'fullscreen' or 'side-by-side' (or whatever they call it) just doesn’t really cut it.