This is the belt from my '04 Electra Glide. It has 110,000 miles on it. I just replaced the belt not because it was worn out, but because the pulley was.
I recently read an entry on a motorcycle forum, where the writer opined, "Chains drive motorcycles, belts hold your dress up." The above belt and pulley have 110 thousand miles on them, the chain sprocket below is from my Sportster after the last Stampede and has a total of 7,000 miles.
Your honor, I rest my case.