[ken]

Or as Frank Vertosick pointed out in his book, mother nature wants life in general to continue, but doesn't give a shit whether any one individual lives or not.

Man-made structures do have some redundancy, but in general we don't build like that. When we install brackets like the one in the picture, we don't install a few extra ones with the expectation that some will fail. We make them much stronger than necessary ("safety factor") so we're sure none will ever fail.

Mother nature can't afford to put all her eggs in one basket. Humans often can't afford not to.

[lonelappde]

Many things are made with finite durability. Perhaps most. Paint chips, air filters clog, lubrication is scratched away, wood rots, tires and brakes wear away.