Why is the nitrogen cycle more complicated than the water cycle or the carbon cycle?

The water cycle and the carbon cycle are much more straightforward than the nitrogen cycle. The nitrogen cycle is much more complicated because its biochemical cycle results in numerous conversions of the nitrogen in multiple chemical forms as it circulates in the atmosphere, lithosphere, and the hydrosphere. Its conversion can be performed in both physical and biological process. Its cycle becomes more complicated because of the way of usage of the nitrogen by the living organisms, where it is used as a nutrient, as part of a certain process, or is released as a waste in different spheres.

it's c (engineer's do their work with mechanical stuff not on any living being)