Can fallen leaves be used as fertilizer? why?

Fallen leaves are used as fertilizer by many people. This is the correct and useful disposal of the leaves, as they rot and become an excellent fertilizer for plants. Burning leaves is a dangerous disposal method. Fallen leaves contain many toxic substances that enter the atmosphere when burned. And when decomposed, they break down into useful compounds due to the vital activity of worms and bacteria. But it is better not to use the leaves as fertilizers, which are located near highways and in places with heavy pollution.