As a former engineer, experience has taught me pretty much anything mechanical will at some point wear down or break due to usage. In the image shown, over time there is a potential for that brass piping forming the tunnel to wear due to the harder steel string rubbing against it. Like wise the fret wire pin securing the pulley has the potential to wear or break off with the tension from the string and the friction as the pulley rotates. It is fair to say that it may take years.
I worked in the print industry before I retired and I was amazed to see paper cut through steel conduit pipe over a period of six months. The pipe was being used to guide a continuous roll of paper exiting a printer and into a guillotine. Most people cant understand how this is possible until I explain that the fibers in the paper are abrasive and file away the metal.