When should you start replacing coin holders/capsules?

This question has bothered me since last night after watching those "cleaning coin" vids on Youtube, and I googled the same question; with no solid answer in sight. When is the right time to replace those coin holders or capsules (regardless of the brand), 2 to 5 years later, 10 years later? I know coins age inevitably and that nothing lasts forever, but what are some techniques or methods that you use to prevent early oxidation or tarnish? Let me know.

Plastic capsules if not exposed to UV light last for centuries why replace them? As long as the materials used in you storage media don't damage your collectables (PVCs etc.) or look ugly like rusty staples or discolored paper flips I can't see a reason for replacement.

Far more important is a stable climate (no extreme temperature changes), lower moisture environment or no direct sunlight for printed collectables. For tarnish don't live next to an old coalpower plant (better for your health too) or store your collection unprotected near other high sulphur compound emitters like open windows near highly frequented roads or high salt content air if you live near the sea.