I have a tmux session that's been running for almost a year with no problems. I don't know how long it will run, but perfect performance for almost a year is good enough for me.

My session has 8 tabs, and one of the tabs (my primary) has 14 sub windows (frames?) showing all kinds of good busy information.

Fair question. My environments are different now, so I have no need to have a session last that long. My longest screen session, like yours was years. My current longest tmux session goes back to April 23 2018.

Admittedly, I'd hope to argue that if I keep sessions open that long I'm the problem.