TL;DR: It depends on the trip.
I hiked for a long time without poles, just because I had never bought any yet. But, for my trip to GUMO, I knew I didn't want to do that kind of up and down over steep rocky switchbacks without them, so I made my own cut from a local bamboo grove (probably less than $10 invested counting all materials). Now after having done that hike, I can confirm that they were a life-saver, possibly literally if they prevent a misstep and subsequent trip over a precipice. I wouldn't want to hike that kind of terrain without poles, even if I was carrying no pack at all.
For flat-ish terrain, on the other hand (which for me would be Davy Crockett National Forest or a local state park), I wouldn't bother. For something in between, say part of the Ouachita Trail for example, I could go either way. If I'm doing climbs from valley to ridge or vice versa, I'd probably take the poles. If I'm staying pretty consistently high or low, I wouldn't. If I were to hike somewhere with no trees, like the middle of the desert or above tree line (though there's nothing like that around here), I might take them just to support my tarp. That, or deal with the weight penalty of my free standing tent and not have to have the poles in my hands the entire time, because they don't collapse.
The journey is more important than the destination.