I’ve posted several links, with tongue-in-cheek titles, to “obvious” science. But in reality, such science in necessary.

‘Duh’ science: Why researchers spend so much time proving the obvious

Scientific studies quantify results, which is important. Even if you know an effect is there, knowing how big the effect is and what variables change the results and by how much gives you insight into how to attack/leverage the phenomenon. Also — and the article only mentions this in passing — conventional wisdom isn’t always right. It’s necessary to do studies to confirm that actions are having the outcomes we think they are, even if nine times out of ten they do. One of the more famous examples is the conventional medical wisdom that peptic ulcers were caused by stress or spicy foods, and how that colored their treatment. Because that conventional wisdom was challenged, we learned that most of these ulcers are cause by the Helicobacter pylori bacterium.