I've heard of musicians who have worn down the keys on pianos, or the frets on a guitar. I've ran in running shoes to the point where holes appeared in the souls. The point is, things we tend to use a lot tend to also wear out.
And right now as I write this blog post, the computer keyboard on my laptop is slowly breaking down.
Of course, the entire disintegration of the computer keyboard would take a long time. Right now only certain individual keys are affected. I can't remember when the plastic on the keys began to chip and fly away. I think I've had this computer for several years and I know that I've used this machine every day. And then one day you notice the small holes beginning to form on the "N" key, the "A" key and the "S" key have gotten bigger.
I'm sure several keys will stay the same, but I'm sure others will continue to erode or begin the process. To me, worn our computer keyboard keys is a badge of honor, a sign of commitment.