I use every feature it offers: scroll back, copy buffers, window splitting/management, different sessions for different projects, etc. I do a lot of work on different servers (it’s not uncommon for me to be connected to 4 different servers at once) and having tmux on all of them means I can always pick up right where I left off. If I’m starting a long build on a Friday afternoon, no problem: start it in the remote tmux session and simply detach from tmux and log off. When I come back on Monday morning, I just SSH back in, reattach to the tmux server, and it’s like I never left.
Tmux has a steep learning curve for sure, but if you are a terminal user at all I cannot recommend it highly enough. It’s a game changer.