I don't know what they did in the later versions of Godot (I think around version 4.4), but in one the versions earlier, after I turned on emulate 3 button mouse I could rotate the camera around the center by holding alt and moving the mouse.

Maybe I am missing something but after some update the only way I can turn around the camera around the center is through the axis icon in the top right corner by holding the mouse key and moving the mouse on it.

So in my case the options are a downgrade and possibly also redoing some work or getting used to the annoying movement system when I'm on the go in a bus or train (or even at home since I can't sit still in once place) where I can't easily pull out a mouse.