To be fair, stones also usually sink but those red volcanic ones have so much air in them they will float in enough water. And how else would you describe most of these billionaires besides turds full of hot air?
Stool’s ability to float is usually related to air. A high fiber diet and gas can cause stool to float.
A diet high in fiber leads to increased bacterial fermentation during digestion. This produces more air, which can get trapped in stool, causing it to float.
This same source says that too much fat could also cause floating, but from a different article:
Some people think that floating poop is caused by fat, but it’s usually caused by gas. Research has indicated that once floating stools were degassed, they weighed the same as sinking poop. This indicates that gas was responsible for making floating stools float, rather than fat inside the poop.
Because your diet is normal... for anyone who has floating poop, more than likely a fat slob who eats chit tier food. And likely to have a health condition. I just happen to learn about poop a few months ago, since my daughter wanted to know about poop.