I doubt that dentists conspire for us to have bad teeth.

People with bad teeth is literally their main revenue stream?! I wouldn’t put it past them.

I once tried brushing my teeth with baking soda instead of toothpaste for a few weeks. From what I understand, they have about the same level of abrasiveness, so they should be about as good at scrubbing the gunk out of your teeth. The key difference is that toothpaste has fluoride in it. After a while I started having pain/irritation in my mouth and gums. It went away when I went back to toothpaste. So if anyone was looking for anecdotal evidence of fluoride being good for your teeth, there you go.