When I used COSMIC for about a month, I loved the fact that it had mixed a regular DE with TWM features. It had the status bar nicely set up, workspaces readily available and an easy switch right from the status bar to go between different tiling arrangements. They were also building out a good system manager GUI, similar to GNOME. So they had the best of both worlds which was what attracted me to them.
The one thing that discouraged me from it was the way they handled workspaces, just like gnome. You were able to have numbered workspaces, but if a workspace got empty it would automatically rearrange the numbers of the workspaces. So say you had workspaces 1 - 5 open. Workspace 3 became empty, it would then move workspace 4 to 3, and 5 to 4 so it’s numbered 1 - 4. That was a no no for a TWM. If your browsers are on workspace 6, you always want them on workspace 6 even if 1 to 5 are not open.
That was about a year ago, I don’t know if they have changed how that works, but for now I am sticking with Sway on Fedora.