Bro honestly you dont know much about what youre talking about.
"spice" or synthetic weed is just a synthetic cannabinoid mixed with a solvent then sprayed on a base herb (marshmallow leaf, damiana, various others), then the solvent is left to evaporate and the cannabinoid is left in the herbs. Spice has been made out of dozens of different cannabinoids and psychoactive chemicals, so you really can't generalize all spice as the same thing.
ALSO spice is NOT made by the government, in fact every year the government passes laws and bills in an attempt to make these psychoative chemicals illegal and therefore, the spice treated as an illegal substance. Every day chemists are coming up with new "research chemicals" to add in their blends so they stay legal and get people high. jwh series, AM series, countless other usable research chemicals, and the combinations for different types of highs are limitless. The profit margin is quite large as well, it can cost less than $50 to make over an ounce of synthetic weed.