Linux

Not OP but the answer is that having windows on top of each other is mostly useless. 99% of the time, when you're working with multiple windows, you don't want to see just part of the window. So either your window is minimized or somehow tiled. At that point you are using a worse version of a tiling WM. The 1% of the time, you can just make the tiled window float.

The main reason I hear is that it maximizes screen usage and helps avoid/limit the tediousness of having to manage windows.

Not what you're asking for, but I'll give you my perspective as someone who's tried tiling on and off and overall don't like it.

1. Applications work best at certain aspect ratios, having them automatically tiled to different aspect ratios can be annoying
2. Some windows windows/pop-ups have no business being tiled. Like some Yes/No dialogs (not all windows specify a max size which would avoid triggering the tiling) or a simple calculator. And you can specify which ones to have floating, but it requires setup.
3. Sometimes it ends of causing more work than floating environements. Most of the time I only have a max of 2 windows open, but occasionally I'll quickly try to do something then end up with 4-5 windows, at which point that's too many windows and I need to reorganize stuff to continue working. But that usually wouldn't be an issue in a floating environment.
4. Worst of all, just setting up a tiling environment is a nightmare. You have to configure the actual compositor/WM, which tools you want to use with it (bar, launcher, screenshot tool, notifications, screenlocker, etc) and configure all those too, ideally with some basic theming to make them look coherent. But inevitably you end up with missing functionality especially in the modern area where an app might be sandboxed or expecting all xdg-portals to be implemented, which most compositors don't do.

Cosmic is exciting in this regard since it aims to be a fully-featured floating and tiling environment. You could just toggle between them as necessary (or have them on separate workplaces). You also get much better portal support.

Its less work to use keyboard shortcuts to arrange/navigate windows in tiling than it is to use a mouse + alt-tab. Window sizing and placement is something you think about a lot less. Its very fast to flip through various preset window arrangements and usually that's good enough for whatever task.

I find tiling more efficient because

1. I can have predetermined layouts per desktop where my often used programs are.
2. I only have to purposely move windows out of the way if I've made the floating on purpose, and
3. Less mouse use and more keyboard use for changing the layout, resizing windows, changing to another window ...

The more I use tiling, the more advantages I find. At this point I think I could use any desktop as long as I had Krohnkite functioning tiling.

I'm using FancyWM on my Windows 11 work pc. It works quite well for me.