I'll just leave this here before you continue spouting more nonsense

Harmful effects of nicotine

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4363846/

I'm sure even a cursory search for caffeine will reveal some harmful side effects as well. Especially for people with certain conditions

Caffeine increases blood pressure and is associated with arrhythmia. It also disrupts sleep, causing caffeine-induced sleep disorder. Prolonged consumption of caffeine results in dependence, causing withdrawal when dosage is reduced.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5445139/

Caffeine impairs your quality of sleep taken too close to bed, where “too close” is after 12pm.