Have you looked at MaxTo? https://maxto.net
It does not work in the exact same manner as i3wm does; it lets you decide on a set of regions that windows are maximized into (the regions can be a non-uniform grid). This lets you focus on one task at a time. It has great support for hotkeys. At the moment I believe MaxTo is the closest you'll get to i3 on Windows.
I much prefer i3's tiling strategy where it's not predefined, and instead it reacts to how you're using it on the fly. So if you had 2 windows split and you wanted a third window split, you just get that by default without having to define that triple column layout ahead of time.
The only feature that it doesn't have out-of-the-box is an "always on top" option for floating windows (but can be implemented by running a separate AHK script).
When I ran the stable version a few months ago it didn't even act like a tiled window manager. After you open it, all it did was tile a bunch of existing windows automatically, but then if you tried to resize them, it only resized the window that had mouse focus.
i3 would have resized all of the windows to fit so there's no gaps.
Overall it just felt very flaky and it had a lot of screen flickering when moving things around.
Too bad nothing exists like that on Windows. Snapping or splitting 2 windows side by side (the Windows 10 snap feature) isn't enough.
On the bright side most of the other features that you would use along side a tiling wm can be used in Windows, and it's very good.
- AHK to manage global hotkeys and remapping keys
- Keypirinha to launch apps / folder paths with fuzzy search
- DexPot to have multiple virtual desktops that supports moving windows across them (same key binds as i3)
I made a video about 6 months ago showing some of these tools in use at: https://nickjanetakis.com/blog/a-linux-dev-environment-on-wi...
Although I changed a couple of things since then, such as I use Vim instead of VSCode, but I still use the above tools every day. They are really solid.