Sciences is the basis of everything. Science provides an explanation for all events happening around us although some events still require more research e.g. cancer and how the universe came to existence.

Treatments are not just made. They have been investigated by many doctors and scientists who have repeated treatment methods countless times and then have come to conclusions.

Predictions are made first. Then experiments are carried out to prove whether the predictions are correct or not. Based on the results obtained, further research is carried out to know why such results have been obtained. Then they are repeated by fellow scientists and doctors to ensure that they obtain similar results. If they do, then the theory is accepted.
Alternative treatments must also be created because not every patient is the same. Different patients with the same condition may require different treatments because they may have different lifestyles and allergies.

It is true that there is more to healing than just the application of science. People can argue that doctors just give the treatment and “nature does the healing”.

Together with this, a patient must have belief that they are feeling better. This can only happen if they have trust in their doctor and feel comfortable. Doctors are required to do more than just apply their scientific knowledge. They must take into consideration the social and psychological aspects of the treatments to allow patients to feel as comfortable as possible.

There are treatments which have little to no scientific explanation but help to improve a patient’s health. A clear health benefit can be seen.
You can give the example of the Deep Brain Stimulation treatment for Parkinson’s disease.
Even though we would prefer to know how the mechanisms for such treatments work, it is not absolutely necessary as long as the patient’s health is not affected in an undesirable way.