What word means the accumulated damage over a long period of time?

What i'm looking for is a very specific word that describes the wear and tear over a long period of time. Like the indent on old stone stair that have had millions of people walk on them or scratches around a headphone jack on an iPhone from all the times someone has plugged in their headphones.

I thought this word was patina but that only describes the aged look of something not the subtle damage created by constant use over a long period of time. I'm looking forward to seeing what words people come up with.

Attrition

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