I suppose you can make a case for proficiency with bow drill,flint and steel, fire piston, etc but I must admit I just don't get it. it is very easy to carry premium matches w/tinder in a waterproof case, one (or two) Bic lighters, or other modern appliances, which can be lighter than the primitive items. I do use a ferro rod and steel to ignite my iso-butane canister stove - works very well.

I am very often in situations (above timberline, in caves, etc) where conventional fuels are not readily available, so bring on the liquid fuels. I have been in situations here in SoCal where a conventional wood fire is inadvisable or prohibited, although that is a fairly special case.

Certainly not a bad skill to possess, but realistically not all that critical.