Earlier quoted context omitted.
You seem to have... very unusual experience with zippers. I honestly can't remember the last time I had trouble with one or ever having any serious trouble with one.
"very unusual experience with zippers." With respect, I think it's your experience that is very unusual. I reckon you must never go camping and use a sleeping bag with a long zipper or you wouldn't say what you've said. The woman who runs the drycleaning shop near where I live also provides a garment alteration service and her main business is shortening jeans and replacing broken zippers! She even specializes in rep…
Do regular people ever wax their zippers? (ChatGPT says it might be done by sailors or leatherworkers on occasion, for whatever that's worth.)