I'm pretty convinced that fluoride is not needed in water or toothpaste. My family of four uses reverse osmosis to remove fluoride from tap, and have used fluoride-free toothpaste for the last 10 years. We all have impeccable dental health despite regular sugar in our diets, but we do practice strict flossing and brushing.
There's actually a lot of evidence that you're right. But only in places where flouride toothpaste use is high. It seems it mostly makes a difference in areas where use of flouride toothpaste isn't widespread. In areas where it is, the risk of dental flourosis (though a relatively small risk) seems to outweigh the potential benefits
