As for neck carry, I think it is among the most practical; easily available, you tuck it under your shirt when not in use and move it out when required. Even work in winter with heavy clothing on.
Well as I said, it is very unlikely and I have disregarded it so far without much trouble, yet there are plenty of sports or activities like factory working where that kind of lace is strictly forbidden, and while outdoors, it has happened to me (or seen happen) a handful of times to tumble down a hill or fall in thick bushes, and I've happened on some occasions to work in trees or up a scaffold... And it is often in those occasions when you want both hands available that neck knives are interesting. Plus I like to keep a large loop for neck shealths for easy manipulation.
So still unlikely, and it probably won't ever happen to most people on this board, yet I can see it happen.
Nothing wrong with that, those are still quite speciality items you won't find in a cabin or in your home if you are in a rush.
Funny after reading the first posts, I came with a similar idea.
Plenty of good advice so far, thanks everybody.