This article is bad and should feel bad
1) Romans didnt use salt as a currency the salt salary conection
is a big fat we dont know probably metaphorical.
2) The chinese tax thing diffusing throughout the ancient world is doubtful because we know the romans instituted a salt tax in 204 BC less than a hundred years, compared to say gunpowder which takes roughly 300-ish years to diffuse through Eurasia.
3) The contention that salt taxes increased living standards is bizarre when there are actual revolts that happened partly due to the salt tax.
4) this article is bad and should feel bad.