Poles are critical for me when I have to wade across a stream. I just did a 9-mile, 2850 +/- day hike today and really used my poles. Poles are great for off-trail travel. I now use them to just touch rocks when I have to hop a lot of talus- it helps my balance. And poles suffice on lower angle snow when I do not need traction devices.

never have considered my poles as part of my pack weight, because I always carry them in my hands. I am not quite sure why you are so worried about the weight of the poles. Used properly, they actually take weight off your feet.

And I too, have had the swelling/numb hand issue completely mitigated by using poles.

For me the only down-side is that they make taking photos more awkward. And, of course, after a rest break, you have to remember to pick them up!