Why do we need to add manure in the soil, why not the chemicals?

We need to add manure in the soil, not the chemicals, because manure has many benefits that we cannot get from chemical fertilizers.

Manures are good for the environment as they have recycled nutrients and make the decomposing of garbage easier, increases the amount of organic matter in the soil, and provides humus to plant.

While, chemical fertilizers harm the environment, do not support microbiological life in the soil, does not add any organic material to the soil, and doesn’t provide humus to plant.