In a way, science is a process of creating a model. To create a model, you first need evidence (i.e. data) and then you form hypothesis which your proposed model. Then you make prediction using your model that wasn't known before. If predictions continues to remain true over time then you have higher confidence in your model. However, a true scientist would never set his/her confidence to 1.0 in any model because all models are eventually wrong and needs to be improved further. So the science is the process of continuously gathering evidence, improving model and remain skeptical that you might be wrong. It is very much like training a machine learned model using training data. Most soft sciences do the first two steps and bypass everything else. It's like you created ML model, you had good result on training data but you never tested your model on hold out set, assumed your model was good enough and just moved on to make a press release.

We don't know the mechanisms of plenty of things that we accept as proven with scientific principles, like most of pharmacy.

And what about physics before Newton? Or before Einstein? In fact, we still don't know exactly how gravity works. Or magnetism. At what point are you drawing the line of being able to "elaborate the exact mechanism"?