It is important to remember in the testing of whether the impact is there, it is also estimating the size of that effect which makes it valuable.

In addition, there are a lot of things that we would have said a similar thing to that were shown to be false upon doing the actual research. People are prone to all sorts of cognitive biases that make us think we know some things that aren’t true at all. A common thing discussed is “learning styles” (eg auditory, visual, tactile) which is spouted as fact by many and I would expect quite a number of people to not think it is even worth studying because it is so clearly true. Despite this, there is a large body of evidence showing that this is not a thing. It is important to have a healthy level of exploring of what we think we know to continue developing as individuals and a society