I've tried many things for both macOS and Windows to get that "i3wm feel" but nothing quite scratches the itch. macOS can get close but sadly requires disabling security features in macOS for deep integration and that is something I don't care to entertain personally. So I make do with macOS's Spaces and Magnet (a nice third party application for hotkey window 'snapping', there are good free/oss alternatives also such as Spectacle).
Windows 11 is getting some more powerful snapping options plus Microsoft's Fancy Zones PowerToy is quite nice although a far cry from i3 or similar.
When on a laptop a twm is freakin' awesome* as dealing with overlapping windows is such a pain in the ass on a 13-15" screen. Is a little sad when I see people fiddling about to get two or three windows resized using a trackpad.
Hopefully with the enhancements in Windows 11 we will see more progress towards automatic window layout and management . While unlikely it would be nice if Apple take note for Microsoft's changes also.
*pun intended ;)