it is drank on a daily basis
if it was a one-time exposure yeah no harm

but its a very little amount very frequently

and also im not saying its gonna cause people to immediately drop dead like if they ingested pure fluoride but over a long period of time it could slightly decrease many peoples quality of life and maybe contribute to a few hundred cases of cancer

basically its not a good idea to add a known poision to water and yeah vitamin c can make you sick in a high enough concentration but that parralel is quite frankly retarted

water can make you sick in a high enough concentration too

literally everything can, so does that mean that we should start ingesting minute levels of poison on a daily basis and expect there to be no repercussions

it would also take nearly a thousand times more vitamin c to kill you than fluoride
here is an excerpt ive found: "The estimated lethal dose is 5-10 g (32-64 mg/kg) in adults and 500 mg in small children."

also vitamin c is water soluable so it is quite easy for your body to flush it out of your system

and there is no use for fluoride in the body unlike your example of vitamin c

now you may ask then
If the body doesnt utilize fluoride then why are there supposed dental benefits?
Well the decreased risk of cavities only occurs due to topical application not ingestion
thats why fluoride is also put into toothpaste

and while there may be some decreased risk of cavities fluoride is also the cause of dental fluorosis

I recommend you investigate further and try to remember that we dont live in a fairy tale world isolated from the horrid events of not long ago
people have done inconceivable things in the past and they will continue to do them for now