FWIW, you can do a split-window layout without fullscreen by holding Option while hovering over the green traffic light.
Personally I use this (or even resize or rearrange windows) very rarely though. Most of the time if I need two documents side by side it’s in an IDE that supports panes.
As for command-tab, it’s deeper than just one command. The macOS windowing model is just fundamentally different with how windows are not equal to processes. A toggle would need to change the windowing model of the OS to work properly.
Personally I use this (or even resize or rearrange windows) very rarely though. Most of the time if I need two documents side by side it’s in an IDE that supports panes.
As for command-tab, it’s deeper than just one command. The macOS windowing model is just fundamentally different with how windows are not equal to processes. A toggle would need to change the windowing model of the OS to work properly.