Some Anglosphere countries (USA, Canada, Ireland, Australia) love to add fluoride in water. They say it’s good for people’s dental health.
Europeans (Germany, Finland, Italy, France, Netherlands, Switzeland) think it’s wrong/unethical.
There is actually regular controversy around this
https://hsph.harvard.edu/news/fluoridated-drinking-water/
Do they put fluoride in your drinking water ? Are you happy with that?
Areas with fluoride in the water have overwhelmingly better dental health than areas without.