How leaves become fertile soil

Realizing that google is ruthless in destroying the life and finances of domain investors, link sellers in India, for the last few years, the google competitor has decided to spend some time gardening, as it is very difficult to end the google, tata masterminded SEX, bribery racket,online financial fraud.
In 2016, the google competitor had tried to grow amarathus in some pots which she had.
It appears that amaranthus will only flourish in fertile soil, so hardly any plants were growing
However in 2017, some of the pots were filled with dried and decaying leaves from the trees,mainly teak and raj amla tree and some earthworms
It was observed that the soil was extremely fertile, and the amarathus plant grew quickly in the leaf soil
So if a person does not care for what others say about the cleanliness of their garden ,and allows the fallen leaves in their front yard and backyard to accumulate, they will get a lot of fertile soil after a year.