I meet folks all the time who don't know about tmux and this blows their mind. Likewise having multiple panes in a SSH session... and with mouse control!
set -g mouse on
tmux is bliss! :help terminal.txte.g. I write and yank: r!fancy command arg1 arg2 ..
Then go to the next line and do :@" This will run the command (well execute the colon mode command) and read back the results.
edit: The nice thing about this is that I can do this as a progressing document (command, output, command, output) and scroll back to see what I have done and what the result was.
I do use screen for the detach/reattach feature sometimes. But, ever since I started regularly using X Windows instead of a vt220, I use my window manager to multiplex. I will open multiple xterms and emacs X windows ("frames" in emacs terminology). I will never sub-divide one xterm or one emacs frame, and I only learned the command to undo an accidental windowing subdivide, much like I learned to abort from vi/vim if I accidentally get dropped into one due to a missing VISUAL environment variable.
If I can launch emacs through ssh with X forwarding, I will. If not, I'll open multiple xterms and multiple ssh sessions and run many emacs instances in -nw mode. Once in a while, I'll mount the remote files via sshfs and use my local workflow. Even locally, I am just as likely to have multiple emacs instances open as multiple frames from one instance, since I prefer to find files and open them from the shell prompt than screw around with file-opening dialogs in the editor.
Even back in the vt220 days, I was much more likely to use shell job commands to background and foreground for multiplexing rather than want to subdivide the already small console.
My workstation and my laptop computer are my interfaces to the world for 99.9% of my interactions. Without them, I am not working. The only exceptions might be touching a KVM console on a server in our machine room to see diagnostics (otherwise I would use SSH from my office) or a lab computer where I'd only be running local browser or demos.
Fedora Magazine has a pretty decent guide for setting up i3 to a functional state and I can recommend it: https://fedoramagazine.org/getting-started-i3-window-manager...