zip ties, duct-tape, coat-hanger wire, bailing twine, are all very useful items and none of them make much of a dent in my PSK plans. I have a snip of duct-tape in there and a bit of thin nylon twine but zip ties take up enough room as to cut into my room for snare wire. I could probably use the snare wire for whatever I could do with zip-ties but not the other way round.

OTOH in my BOB / home preparedness kits I have a big box of zip-ties in varying sizes along with a really large hank of paracord and some "real" rope and block and tackle. I could use my BOB / home preparedness kit to stabilize a building enough to enter and retrieve items or people. I don't plan on doing something of that nature with my PSK.

My PSK is for surviving in emergency situations which could be survived out of pocket. If I faced collapsed building scenario with my PSK only I would get out and stay out. Then I would want enough cordage to establish shelter from expedient material. Zip-ties could help here. But I also will have other needs such as drinking, eating, signaling, defending, navigating and occasionally medicating. These needs all compete for space in my Altoids tin. I don't have sufficient room in there for something that is not as versatile as duct-tape. Zip ties only lash things together. You can't use them to supplement your fishing line after that big bass swims off with your first 20 feet of monofiliment. But if you happen to snare a deer and don't have to fish you can use the monofiliment to lash together your smoke house to make jerky out of that deer.