case reports as such have no scientific value, i agree with this but some cases which are rare and some  medical persons who don't have idea for further management, will get direction for management. in cases which are common but medical persons unable to treat by the treatment line as he know, will get new method of treatment as reported in various case reports.

Case reports are included in evidence based medicine https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4719170/

What about cases like these (link provided) that could alter our well established protocols, particularly in surgical part of medicinal practice. Serendipity!

Hong JM,Cho AR ,Choi SA. Accidental intrathecal injection of dopamine hydrochloride resulting in analgesic effects. Korean J Anesthesiol. 2014 Dec; 67(Suppl): S49–S50.

Additionally, regarding science itself, a quote by Freud:

“We have often heard it maintained that sciences should be built up on clear and sharply defined basic concepts. In actual fact no science, not even the most exact, begins with such definitions. The true beginning of scientific activity consists rather in describing phenomena and then in proceeding to group, classify and correlate them. Even at the stage of description it is not possible to avoid applying certain abstract ideas to the material in hand, ideas derived from somewhere or other but certainly not from the new observations alone. Such ideas—which will later become the basic concepts of the science—are still more indispensable as the material is further worked over (Freud, 1915)” (Instincts and their Vicissitudes. 1915).

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4295978/pdf/kjae-67-S49.pdf

N of 1 are the higher herarchy of evidence

They are difficult to do but if you do it then it can change everything

A good and interesting question

I see the case increasingly seen as the expert level professional level rather than as a contribution to science in the academic sphere!