I mean, whatever money value you want to attach, you’re still burning plenty of fossil fuels needlessly in it’s manufacture, transport and application. Takes up people’s time which could potentially be spent on more important things also. Just to spitball a few things that could be gained.

https://pmc.ncbi.nlm.nih.gov/articles/PMC6195894/

You made a typo, fixed it for you

Fluoride does have some downsides, the major upside is dental caries prevention, because of the high carbohydrate default diet caries are very common