Worms produce soil with an abundance of "micronutrients" and the good bacteria and stuff that the plants need. their castings do not contain heavy amounts of the macro stuff like nitrogen, p, or K. the micro are more important I think as long as the others are there in reasonable amounts. .

worms don't produce "nutrient rich soil", they produce worm castings, that are high in beneficial soil bacteria .... a worms diet is actually the microbes that cause organic decomposition, not so much the organic material itself .... the bacteria break down the primary carbon and nitrogen components of things to grow and reproduce themselves, the worms slurp them up [no teeth!!], digest a fraction, eliminate the rest [they're very poor digesters], and will repeat that endlessly as long as there's enough moisture and microbial activity

as wfike sez, it's the macros that predominate, the kitchen scraps, like the foods we eat, are high in a wide range of trace elements/minerals, and paper [carbon] is too, and grows lots of tasty bacteria and fungi

Bill

They types of grit you give your worms may also affect the nutrient content of your castings. Powdered egg shells will increase the calcium in the end product. Some worm providers sell volcanic grit that has a very large number of trace minerals to help increase the traces in your end product.