This is because I have a few applications (Firefox, Terminal) that are really not applications in and of themselves; the applications are really Outlook, JIRA, Confluence, Slack, OpenShift (logged in as cluster admin), OpenShift (logged in as my regular user), that quick terminal session I opened to work on a script, the SSH connection to an OpenStack director, the 'oc rsh' command that I'm using to administrate a PostgreSQL database running in OpenShift, and so on.
This becomes far worse when using multiple monitors. Say I have teams hanging around on my secondary monitor to keep an eye on stuff. I literally just now alt-tabbed into a terminal and then alt-tabbed back to continue writing this comment. As a result, I'm back in Firefox on my primary monitor (as expected) but now I have an unwanted random Firefox window that I forgot was even open on top of Teams on my secondary monitor!
The only window manager I've ever been at home with while using multiple applications, workspaces and monitors has been i3. Specifically I love how it manages multiple monitors in that each has a current workspace, but workspaces are not bound to a particular monitor. So I was able to have my secondary monitor always showing my 'Slack and email' workspace, and switch between my multiple task-based workspaces on my primary monitor and never get confused like I with GNOME where I want to switch to my email tab but to get there I have to remember ahead of time that I have to switch to my first workspace, then switch applications to Firefox, then switch windows to the one with Outlook in it, and finally switch to the Outlook tab...
Anyway. This project looks awesome and I will try it out!