Heat is the biggest factor in this part of Arizona, and the climate here runs in the severe band for heat exposure. A garage that sits in full sun most of the day pushes temperatures inside well past what the cable's lubrication and the pulley's grease were built to handle long-term, and that's what dries out the strands and lets them start fraying where the cable rides over the pulley - the exact wear pattern we see on Sun Lakes calls more than almost anything else.
The other factor is simply age matching the housing stock. With a median build year around 1990 across the area, a cable that's never been replaced has had three decades of cycling through summers that regularly stress the galvanizing. Add in that extension-spring setups put more direct load on the cable than torsion systems do, and you get a part that's overdue for failure on a lot of these doors, whether or not the spring itself has ever been touched. We're honest that a frayed cable usually means the opposite-side cable and pulley aren't far behind - replacing one and leaving its mate original rarely buys you much time.