[mancerayder]

fluoride is safe and effective and because it's so widespread in use, even if you only drink bottled water you're probably getting secondary exposure from other food/drink sources. And if you brush your teeth regularly with a fluoride toothpaste, then you've got that delivery mechanism covering you as well. In the end, the public health benefits are there because fluoridation is pervasive and hard to avoid. By similar argument, you probably also don't have an iodine deficiency because of all the iodized salt in use.

So, I don't think you're factually wrong in most of what you said. But I have to say, you're saying that it's pervasive in other sources besides tap water (since you raise other food/drink sources), but still in your first sentence asserting that it belongs in drinking water.

So I ask you, if these other sources of beneficial fluoride exist (like our toothpaste, or even food/drinks), why would it need to be added to the drinking water?

And why, of all things, would they choose fluoride to add to the drinking water, and not the myriad other minerals/vitamins we're deficient of. I know that's proposterous to imagine - but fluoride somehow made it.

[extra88]

The secondary food/drink sources contain fluoridation because they're prepared using tap water. If you don't drink tap water, you'll still get some exposure but if you take the fluoride out of the tap water, you won't. If literally everybody brushed their teeth with fluoride toothpaste, I don't know if adding it to the water would still be worthwhile; it might be good for very small children before they have enough teeth to start brushing.

As already stated, fluoride is cheap and safe in the water. Other substances aren't cheap, have risk of overdosing (possibly only for people with sensitivities), or are readily supplied through diet. Some substances may also not be transportable through a water system because they too readily bind with others or don't remain in suspension long enough to reach your faucet.