I have the strong sense Facebook is dying off with all but the oldest and most boring of people.

And I agree, if you can't delete your account for whatever reason, (like, let's say, your parents don't know how to text unless it's through the Facebook app,) then the next best thing is delete the app.

And I stay signed out on the browser too. If I ever need to sign it in, I open a private window, use it quickly, and close the session. Prevents me from idly navigating to it when I'm bored at work. (The main reason I have two factor enabled is not to protect my account, rather just to make it harder to sign in so that I think twice about doing it.)