I think it's just a prettier architecture - obviously both ways work, but if the WM has good splitting, applications don't have to bother with windows and layou

I think it's just a prettier architecture - obviously both ways work, but if the WM has good splitting, applications don't have to bother with windows and layout implementations. Furthermore I like to switch between "windows" (rectangles in a tiling - e.g. vertical/horizontal splits - context) or in general rearranging the layout using input controls on the WM layer, so that it works the same across all applications and not just in a terminal emulator context. In the end it's personal choice, however it has some benefits, as the same workflow works across applications. Obviously this requires a WM itself and does not work in a Linux console context (which is supported by tmux and screen), but I mostly run X11 with a WM anyway.