i3 changed my life. As many workspaces as I want, any window arrangement I want, including full screen. No wasted space. Wrote my own script to add nvidia GPU information to the bar. Bound important programs like browsers and terminals to shortcuts. It's amazing, it just gets out of my way and I get frustrated whenever I have to use anything else.
TLDR: global workspace span across all monitors. Changing workspace change for all monitors (Similar to what happen in windows & macos). In my opinion, it allows for a better separation between workspaces/tasks when working with multiple monitors.
It's an MVP/alpha software. Need some optimisations but it does the job (been using it daily for over a year now).