Plenty of reason for it. Even small amounts are toxic and raise your risk of cancer, liver disease, f*k up your sleep etc.
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
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5445139/
Sun
Air
Cars
Electricity
Lack of universal healthcare
Industrial Development
Politicians
Life is the leading cause of death