Cavities are also found in other mammals; they're not even just a human problem. Something like 5% of dogs get cavities. If you have an older dog and get their teeth cleaned, some might need to be pulled.

I even saw something about cavities in dolphins... and, if I remember right, the thing about humans not getting cavities before the advent of the modern diet stems from a dentist who had some unorthodox theories about dental care that were unsupported by systematic research.

Oh, it's the Weston Price foundation people who make that claim...

https://rationalwiki.org/wiki/Weston_A._Price_Foundation

https://sciencebasedmedicine.org/sbm-weston-prices-appalling...