Damien

They can do it. Flouride isn't universally added to water in Western nations. France doesn't add it nor do many European countries (although they add it to salt for some reason). We added it because of a concern over dental health.

I think now people are better at dental hygiene and have fluoride toothpaste so it's less pressing. Adding it to water is much more effective when people aren't brushing their teeth.

Fluoride is perfectly safe though. It's just this bro-science where a community of people have decided it's not safe because in large amounts it's dangerous but a lot of healthy and safe things are in excessive amounts. You'll never expose yourself to anything close to dangerous levels unless you start eating pack after pack of toothpaste in one sitting.