Chemistry is a branch of science that deals with chemicals and their bonds and how different things react together. Like every other subject, it has an importance. However, chemistry may be much more important than other subjects because all other kinds of sciences involve the study of matter and the different interactions between matters.
So, basically, chemistry is at the bottom off the science subjects, hence understanding it is essential to understanding anything in the world of science. This is why it is among the few compulsory subjects that every student has to learn in order to improve their understanding of the things around them.