Shat are you basing that on? I searched around online but found the opposite, e.g. https://archive.ph/yws2m

Probably from the preserved skulls of those lucky enough to get preserved. So, you know, good ol survivorship bias.

It’s popular to believe that there is some semi-idealistic past, or at least some better past, that contradicts any notion of progress. This is supported by lack of evidence once you go far enough back, you can kind of make your own narrative unless you stick to what little evidence is available.

Yeah. Since the comment mentioned grains specifically, I wondered if it was coming from a "paleo" diet perspective.

Its from the perspective of the things that cause tooth decay and their relatively recent addition to human diets.

Processed/refined sugar for sure. But our ancestors in many parts of the world would have had plenty of access to fructose and other natural sugars, which can certainly cause tooth decay.

True

You would just die of a million other things like hunger, or spoiled food, or starvation, etc, etc