This may be too Talebian a reaction, but isn't the track record of "take this-doesn't-occur-in-significant-quanities-in-food chemical and your health will improve" quite poor? Non-food chemicals are often very useful for acute interventions (e.g. antibiotics, chemotherapy), but at least in modern times, they almost always do more harm than good when taken long-term.
(To avoid getting sidetracked by chronic medicines that some people swear by, I'm directing this point more at non-food drugs that are designed to take people from normal health to great health rather than from a disease state back to normal.)
Googled "Talebian" and came up dry, but yeah. One thing that comes to mind that's used widely to thicken things like non-dairy milks (Soy/Rice/Almond) or anything that needs to be thickened/gelled is carrageenan, a seaweed extract that's been tied in multiple peer-reviewed animal studies to cancer.
Google instead "Nassim Taleb", in particular his ideas surrounding iatrogenics (harm done by the healer), and "via negativa" as a heuristic for fixing systemic problems, i.e., removing things (chemicals/drugs) from a system (human body) to reduce the complexity of interactions and side effects.
Where do you get "your health will improve"? The point of caffeine is not to improve your health. It's to improve your mental functioning. Mental functioning is not something our brains evolved for. In fact our brains are quite profoundly flawed for that task.
(To avoid getting sidetracked by chronic medicines that some people swear by, I'm directing this point more at non-food drugs that are designed to take people from normal health to great health rather than from a disease state back to normal.)