IMHO the distributor car and rotor are best replaced on a schedule, I do mine at about 40k miles. (For me that is about every 10 months.) Or you should at least inspect and clean say every year. The wires I usually run until a problem, although they probably should be done on nice summer days and not cold winter nights - which is when the problems usual show up. If over 100k miles I'd say replace.

Neither is like timing belt, no engine damage if they fail. However, both can give problem starts, or no start, in cold or wet weather. And both give warning signs a upcoming failure (hard starts, rough running, etc) especially in bad weather.