I developed plantar fasciitis about a year and a half ago. I went to a Podiatrist who specializes in runners and walkers, and who is of the opinion that poor footwear is the cause of most foot problems. Not the cause of the injury itself, in the case of plantar fasciitis, but that wearing poor footwear over many years "sets you up" for foot problems.
Most shoes have some heel elevation, and many have a lot of toe spring (they turn up at the toe.) These allow the muscles at the back of the leg to shorten, and the same with the muscles and tendons at the front of the leg. Combined with a narrow toe box which pushes the big toe toward the other toes, these forces pull on the plantar fascia in opposing directions. Over a period of many years, that takes its toll. Note that this is my interpretation of what my doctor said...not his exact words. If you're interested, here's a link to his web site:http://www.nwfootankle.com/
With his guidance, here's how I treated my plantar fasciitis: I taped the bottom of my foot like this, except I only used two pieces of tape, with a third piece going cross-wise under the arch to help the first two pieces stick:http://heelspurs.com/tape.html
I also did stretching exercises for both the back and front of my leg(s), and bought larger, wider shoes, and wore sandals when I could. I also used silicone inserts for a while, to get my big toe separated from the others (there are supposed to be gaps between your toes.) This is a slow-healing injury, and I taped my foot for close to a year. I avoided
arch support, and continue to do so. To his credit, my doctor offered me the more traditional treatment, consisting of orthotics, cortisone, and possible surgery as a last resort. I'm glad I didn't go that way. At this point, it's fairly well healed, although once in a great while I'll feel a little twinge.
I used to wear Superfeet insoles, thinking I was doing something good for my feet. Now, I'm inclined to think I was weakening them. In those days (pre-plantar fasciitis), when I occasionally went walking in sandals or sneakers, my feet would ache after about five miles, but were fine for much longer distances wearing boots with the Superfeet. Now, I no longer get the five-mile ache wearing sandals. For hiking, I have a pair of Merrell Radius low-cut trail shoes, and a pair of Keen Targhee mid-height boots, both a size larger than what I measure. Neither are perfect, but better than the Lowas I used before.
To try and answer your original question...the lightweight boots won't last as long as heavy leather boots, and often can't be resoled. How long any boots last depends on how often and where they're used, and how they're maintained. If your leather boots are the traditional, somewhat heavy, stiff, type, I'd consider a more flexible lightweight replacement. The Keen and Merrell shoes I mentioned might be worth a look.
Sorry to be so long-winded, but the subject pushes my buttons. I realize that everyone's feet are different, and some people may need arch support, etc., but there's a lot of B.S. in the footwear world, and a lot of conflicting information about plantar fasciitis. Or plantar fasciosis, as some doctors say it should be called.