Most of the doors we service sit on houses built between 1938 and 2003, with the bulk of that stock going up in the 1960s and 70s across the roughly 80 named subdivisions we cover between Lisle and Bloomingdale. That's a wide spread of hardware ages under one roof style. A door installed when a 1970s split-level went up has had five decades of temperature swings to work on its springs, and a door from a 1990s build is entering the stretch where torsion springs and nylon rollers start giving out without warning.
The cold-moderate climate here is the other half of the problem. Steel contracts in winter and expands in summer, and that cycle works on the weak points first: spring coils losing tension, track brackets loosening from repeated freeze-thaw movement, and lubricant on rollers and hinges thinning out or gumming up depending on the season. None of this is dramatic - it's slow wear that shows up as a five-minute annual check would have caught, but a skipped year lets it turn into a stuck door or a snapped cable on a cold morning.
Houses from the older end of that 1938-2003 range are more likely to still have original hardware nobody's touched, which is exactly the hardware most due for a look.