The idea of "quantifiable" vs "unquantifiable" in worldbuilding.

I think back to the discussion on guns in fantasy settings, and it got me thinking of larger, existential things we allow and implement yet gloss over in fantasy worldbuilding.

For example, certain foods found in locations that cannot support the plants and animals to raise, cultivate, and process them. We don't think too hard about the fantasy chocolate trade, and it's fun to see a small dragon run a bakery serving all kinds of various chocolate pastries. Or about working plumbing.

Yet when we add guns, there is a whole trunk of baggage that comes with it.

And the core of all this is when we see something "quantifiable" vs "unquantifiable." We can't measure how strong dragon hide is, but we can measure how many shots a human can take before dying to a gun, and the quantifiable continues to stick in our heads.

However, there seems to be a delineating line between what is quantifiable and acceptance (i.e. food, metals, etc.), and what is quantifiable but controversial (i.e. guns).

I'm curious if there are other instances of something "quantifiable but controversial" in addition to guns.

How does one approach the idea of "quantifiable" vs "unquantifiable" in worldbuilding?