Synthetic fertilizers are an important part of agriculture because the main goal for farmers is to quickly grow food and yield as much as possible. The use of synthetic fertilizers allows soils to have readily available nutrients. A common question is why can't we use manure, compost etc. as a natural form of fertilizer? The answers to this question are: first, it is not cost effective because farms are not located close to each other and the useful contents of manure are lost during transportation. Second, it will not be readily available for the plants; meaning you must allow time for decomposition and then plant uptake, compared to synthetic fertilizer, which is readily available and ready for plant uptake.
A really simple way to think about it is to imagine your teenage son coming home after a long day at school.
Son: Mom, when will dinner be ready?
Mom: I have to wait for the meat to defrost...
Son: **slowly dying from hunger**, **weak and shriveled in a corner**
Think about the above example and understand how important it is to support farmers who use synthetic fertilizer; use of synthetic fertilizer is definitely regulated to ensure safety and food security.