A door and opener system installed around 1974 was built assuming a certain amount of maintenance that most homeowners never do - spring lubrication, cable inspection, track alignment checks. Fifty years on, the parts that fail first are the ones under constant tension: torsion springs, lift cables, and the drums they wind around. On a house from this era, a spring that's still original is well past any reasonable service life, and when it lets go, it usually takes a cable with it. The mild temperate climate across the area is one thing working in your favor - you're not dealing with the freeze-thaw cycling that cracks hardware in colder states, so a lot of the wear here comes down to age and cycle count rather than weather damage. That's a narrower, more predictable set of failures, which is useful information when you're deciding whether to repair or replace.