Sure, soil testing is always important but most U.S. soils are deficient in something. Buying what is 'needed' isn't the full story. For us, in trying to bring our soils back to fertile health, a blanket of multiple trace minerals isn't a luxury, it's a necessity. And you don't need much. Check out the age-old Law of the Minimum, via Soil Nutrient Management of Maui: "If any micronutrient is deficient, the growth of the entire plant will not reach maximum yield."
https://www.ctahr.hawaii.edu/mauisoil/c_nutrients.aspx
