I need support with this Statistics question so I can learn better.

It is hard to believe that randomized control trials are known as a weak from of evidence. Since it has a proven cause and effect results in phenomena. The use of control and intervention of one study falls short to the colossal amount of information that the study needs to be evaluated against in order to be used into practice. It is understandable, that in order to be applied it needs to be evaluated with different kind of scenarios and patients. This is where systematic reviews come into play since they collate trial data to evidence in order to be used in clinical practice