A door built for a 1990-era house wasn't engineered with today's heat load in mind, and Arizona's HEAT climate band is classified severe for a reason. Track brackets on older installs were often fastened with fewer lag screws per side than current code calls for, and thirty years of expansion and contraction loosens them further. Add a summer where the garage hits triple digits for months, and the wood jamb the bracket is screwed into starts to give. Once one bracket walks even a quarter inch out of plane, the rollers start riding the edge of the track instead of the channel, and it's only a matter of time before one jumps clean out.
This is less about a single bad part and more about the whole system aging together - track, bracket, rollers, and jamb all loosening at close to the same rate because they were all installed the same year.