My usage of tmux gradually dwindled when I started using i3wm/sway.

I really needed spilt and tabbed windows. My window manager does that for me, and I can mix terminal windows and browser windows and windows of any other non-terminal program.

I group windows on different workspaces. I only need a few, I have up to ten configured, but could have infinitely more if needed.

I still use tmux for window persistence or remote servers. For me, that's a very infrequent use. Not even once a week.