The reasoning for creating a hypothesis and conducting an experiment is because the hypothesis is at the heart of the project itself.
A hypothesis is defined as
'a proposition assumed as a premise in an argument'
Scientifically speaking, a hypothesis is a "testable statement". The statement that you make constitutes the assumption of cause or result of something that you will prove to be right or wrong.
Hence, the hypothesis is the driving force behind the scientific inquiry.
To show the importance of a hypothesis, think about any question that you google online, or think about a curious comment that caused you to wonder about it. All the ideas and questions about something are your "research questions". The preliminary answer that you give the sum of all those questions are your hypothesis. It will not be proved correctly or incorrectly until you conduct the proper steps of investigation.
Therefore, the reason why we formulate hypotheses during scientific inquiry is because the hypothesis helps us move the investigation forward. The need for knowledge about the accuracy or inaccuracy behind a statement is the reasoning for creating a hypothesis and conducting an experiment about it.