While it is nice to have a bit more equipment than one can stuff into an altoids tin, it is the perfect shape to carry essentials on body without any significant bumps or protrusions that can impede egress from confined spaces, like an aircraft fuselage.

I don't fly non-commercially all that often, but when I did, it was worth packing about two altoids with goodies, just in case, and keeping them on body, along with my belt knife and survival keyring.

I really like the tobacco tin container, since that gives you something to heat water in, and a lot more space, but the trade off is its bulkiness.