in fairness,

pms is preventive maintenance service.
it's to prevent breakdowns, usually by replacing items before they break down.
sometimes, replacement schedule is more about time or km, and not "how it looks or feels".
for obvious reasons, they're very meticulous about these in airplanes.
sometimes it may appear that they're too meticulous on cars. but that's probably a personal thing...

one can always decline the casa's proposed course of replacement activity...