When you hit F5 (copy) or F6 (move) you typically get a dialog with the destination of the action where the other pane is pre-entered as a default so can just hit Return to start, but which you can also override by typing something before hitting Return. You can type whatever relative or absolute destination you want without having to navigate there explicitly in the other pane. For up/down one directory I personally type .. or the child-directory, if the destination is further away it is often more convenient to navigate there in the other pane.

Moving a few files, no. But a professional move, say something that is going to take more than 30 minutes due to speed/size issues, yes i would use a two-pane tool. Another case would be if the destination had a dynamic ammount of free space, such as to a running server. I would use two panes so i could abort before filling the destination.