For a household cooking daily, wiping down burner caps and checking the ports for visible debris every few weeks catches most buildup before it affects ignition. A deeper cleaning — removing the burner cap and clearing the actual igniter gap — is worth doing every few months, more often in kitchens with heavy grease-producing cooking (searing, frying) since airborne grease settles into those ports faster than most people expect.
If a burner starts clicking longer than usual before it lights, that’s often the earliest sign it’s due for a cleaning, before it progresses to not lighting at all.