Why is correct referencing such a big deal?

Two reasons:

Science develops over time by scientists working together and peer reviewing their work. Science can not be developed in isolation and needs to be evaluated by others through peer reviews to provide critical feedback.
Scientists learn from each other and share their findings with everyone so we can better understand the world around us. The purpose of science is to share a better understanding of the world and therefore allow others to know where the ideas are coming from and go deeper in their thinking.

MLA citations are so easy to generate with online tools

MLA?

MLA stands for the Modern Language Association. It is a professional organization for scholars of language and literature. The MLA also publishes a style guide, the MLA Handbook, which is widely used in academic writing in the humanities.

Google docs

Google Docs has a built-in citation generator that makes it easy to create citations. It is also a convenient tool for creating bibliographies.

EasyBib

EasyBib is another free online tool that can help you create citations in a variety of different styles. It is easy to use and provides clear instructions on how to cite different types of sources.

Citation Machine

Citation Machine is a free online tool that can help you create citations in a variety of different styles, including MLA. It is easy to use and provides clear instructions on how to cite different types of sources, such as books, articles, websites, and videos.

IBO official document: Effective citing and referencing