My current everyday pouch has coil zips because I simply could not find a pouch with the other qualities that I'm looking for, that had an actual solid zipper. And I've had so many of these coil loop zippers fail over the years that I actually considered replacing the zippers before even using the pouch daily. Surely I'm not the only person so pedantic about the quality of their equipment.
We'll see in a few years!
> That said, Nylon Coil zippers are “self-healing,” meaning when the zipper accidently opens or closes incorrectly and skips a tooth, these misalignments are easily correctable by merely zipping the slider over the problematic area. On the contrary, misalignments on a Molded zipper usually indicates or results in a damaged tooth, which oftentimes renders the entire zipper inoperable and requires a full zipper replacement. (1)
Like HDD vs. SSD failure, the latter can be sudden.
1: https://perfectex.com/molded-plastic-vs-nylon-coil-zippers/