Belts and chains both break. Ordering a replacement belt will take several days, if not weeks. Removing the broken link from a chain takes a few minutes with

Belts and chains both break. Ordering a replacement belt will take several days, if not weeks. Removing the broken link from a chain takes a few minutes with a portable tool that I carry with me. I can still get to the office on time. Failure-mode operation is more important to me than keeping my hands clean. Sure, my bike's noisy and dirty, but it's a whole lot faster than walking.