Natural groundwater already has some fluoride in it; it's the potability processing that takes it away. So of course a lot of places put it back in.
I see the push to remove it in my country, too. People claim is kills children's brains - but the amount of fluoride to do any damage is so insanely high. You would die of literal water poisoning several times over before you ingested enough fluoride.
Literally anything hurts you if you have too much, that's what 'too much' fucking means. Deciding something is bad because it has an unreachable 'too much' is like refusing to eat bananas because of Chernobyl.
The water here is extremely hard and has a lot of lime. Limescale is inevitable. Yet I don't see people complaining about drinking rocks? Who benefits from blaming fluoride? Where is this fear coming from?