I've used zip ties extensively most of my adult life. There are myriad versions that have different applications. I've used them for lashings for heavy heliax along radio tower legs right down to binding 24 gauge wire in bundles inside mic connectors. They are versatile and quickly deployed. The last emergency shelter I built used willow branches, clear plastic garbage bags, duct tape and zip ties, and the zip ties held up well and expedited the set up. I could've used lashings of paracord just as well, only it would've taken more time, and if I were encumbered or disabled might have been more problematic. I can lash a zip tie with one hand, which would not be possible with zip cord without pre-engineering some sort of fastening setup first. In a survival situation, that could be a significant issue. The type of zip ties I would carry with me for survival work will hold a static load of 100-130 lbs, and should hold up to normal wear and tear and ambient UV for at least 2 years once deployed.

I made a 30 foot chain of zip ties once to hoist an antenna up a pole. It was a waste, but I had no choice, and it worked. The antenna weighed about 20 lbs, and was well below the load limit of the chain.

I replaced the shoelaces in my favorite hiking boots a year and a half ago with paracord, and it is holding up much better than the laces did. The only complaint is I have to double knot the bow or the knot won't hold.

I used to keep a few zip ties around my wrist till one time I was prying the latch open on one to remove it and darned near slit my wrist!!! Now I just keep em in my EDC.

I think the ideal EDC size is the foot long ones in black that are about 4 or 5 mm wide. I'd actually EDC about a dozen or so of those, then a couple about half that size and maybe one or two that are really big, but the big ones tend to get a bit unwieldy to stow. If you need to zip tie something bigger than one zip tie will handle, they do gang easy enough. You can even use zip ties as trip snares if you know what you are doing. They have too much friction in the latch to work as noose snares, though.

Zip ties got used a lot by soldiers for adding gear to belts and packs in Iraq I noticed.