https://en.m.wikipedia.org/wiki/Cord_(unit)
What bothers me is that it, of course, depends how you cut/stack it. Different woods = different density.
Firewood should be sold on based on dry weight, not volume.
A lot of American recipes assume scales are for cocaine dealers and inappropriately use volume and dumb measures at that “a teaspoon???” While European recipes appropriately use grams.
However, none of my cups are actually cups. they're just cups.
It amuses me that these are actual (and accurate) sentences.
And different syrups will have different surface tensions, so a 5mL flattish teaspoon will hold more than a 5mL deep-well
Table salt is made of finer crystals and will make your dish far saltier if you substitute them unknowingly. (Fine table salt packs about 2x the salt into 1tsp than Diamond Kosher -- 2 tsp Diamond Kosher == 1 1/2 tsp Morton Kosher == 1 tsp regular table salt.
Even my cookbooks that do give weights as well as volumes for ingredients like flour, tend to just give measuring spoon amounts for the small additions.
To your cord example, precision just isn't a big deal and I'm sure it's just easier for people selling to throw an approximate volume in their truck than weighing everything.
I mean, how would you measure eggs, down to the gram? Oh, I'm off by 5 grams, let me crack another one.
Sugar, you can usually use half of what the recipe calls for without much consequence.
Etc, etc.