Standing rigging is one of very few things on a yacht with an accepted replacement interval rather than a condition-based one. Insurers and riggers generally work to ten years for stainless wire in UK coastal use, sooner for a boat that races, cruises hard or lives in the Mediterranean sun. The failure mode is what makes the interval matter: 1x19 stainless work-hardens and cracks internally at swage terminals and around the rollers of a furler foil, where you cannot see it, and it fails suddenly under load rather than stretching as a warning.
A rigger's work covers more than the wire. Mast stepping and unstepping, rig tuning under load, furling systems, running rigging and halyard replacement, spreaders, tangs and terminals, chainplate inspection where the deck is involved, mast wiring, sheaves and blocks, deck hardware and (increasingly) synthetic and rod rigging on performance boats. Much of it is inspection: an annual check aloft, a mast-down survey at ten years, and a rig-tension record so tuning changes are deliberate rather than accidental.
It is also safety-critical, so it is one of the jobs on which insurers ask questions. A rig failure claim will invite scrutiny of when the wire was last replaced and by whom, and a well-documented rig service history helps at renewal and at resale.