Palo Alto's housing stock centers on 1963, and across the wider service area most doors date from the 1960s and 70s. Doors from that era were built with steel rollers on steel track as standard - nylon rollers weren't the default the way they are now. Steel-on-steel wears, and without regular lubrication it wears faster: the roller wheel flattens on one side, and you start hearing a rhythmic thunk instead of a smooth roll.
The mild temperate climate here doesn't add rust or extreme temperature swings to the problem the way harsher climates do - this isn't corrosion-driven failure, it's just decades of steel-on-steel friction finally catching up with hardware that was never meant to run maintenance-free for sixty years. That's the pattern we see on originals: a door that's run fine for decades gets loud, then gets stiff, then a roller finally seizes in the track.