Are Hiking Poles useful and worth them money? Absolutely.
When I first started hiking I noticed a lot of people using hiking poles. I thought it was just a phase. I thought these were just one more thing that people bought just to feel like they were real hikers. When I hiked my first 14er, my friend had brought poles with him. He was a few years older than me so I teased him about needing a cane to get up the hill. But I tried them out and I actually saw a big advantage in using them.
Some of the advantages of using hiking poles is that they help you keep good balance and posture. Many people begin to lean forward after hours of hiking especially with a heavy backpack. The poles keep you standing straight and keep you away from aggravating back ache.
The poles are also very helpful on loose gravel to help support you when your feet slip out from under you. They also come in very handy when rock hopping through talus and small boulders. By using the poles you can keep your balance. They are like hand extensions to help you climb down from one boulder to another (not rock climbing, just light scrambling).
Some people even like having poles in their hands to feel save in case of an attack by human or animal in the wild. They give you something easily available to scare off any critters or the rare human attack.
I never hike without them. They are a very valuable addition to my necessary gear. I highly recommend you purchase poles. There are poles of all price ranges and honestly the functionality doesn't change much so a lower end pole may be all you need to get started.