Why does hydrogen not exist in nature?

This is related to the physical properties of hydrogen. Hydrogen is the least dense gas. The average density of air is 29, while that of hydrogen is only 2. Hydrogen will float to the upper atmosphere and spontaneously ignite under high pressure. Therefore, there is no hydrogen in natural air.

No creature in nature can decompose water and release air, and no creature can photosynthesize and release oxygen and hydrogen like plants. Therefore, hydrogen must be produced by artificial reaction.