I've been using i3 (within the larger Regolith package) for a few years now and its hard for me to non-tiling WMs now. However I do think there would be a lot of improvements, especially with large desktop monitors.
One idea I had would be to have a window manager only have a single main window in each desktop and then scaled down windows around the border on the desktop, like the TV in Idiocracy (https://www.soundandvision.com/files/_images/200902/21720091...). Selecting windows would swap out the main window with the scaled version on the border. This would give you the ability to focus on one window that is always centered while seeing scaled versions of all the other window's output.
Maybe this has already been done?