Apparently, caffeine in soft drinks is synthetic. I thought they just used caffeine that is extracted from decaffeinating coffee beans - not so. Also it's barely produced in the US (anymore), and we mostly import it from China.
Neat part is: it doesn't look all that complicated to synthesize and requires some common-ish organic compounds and solvents to make. As a bonus, the "the raw synthetic caffeine often glows - a bluish phosphorence". If anyone is on his Patreon, please give NileRed a nudge to give this a shot; I think it would be right up his alley.
So we can get by without coffee, but short of running your own chemistry lab, it's going to be a bit before industry can ramp up production of the synthetic stuff. Meanwhile, caffeinated beverages across the board would be more expensive were synthetic caffeine a part of any tariff scheme.