And by that logic we know that these procedures must've worked since they didn't kill all the people the were used on, hence they were passed down for generations and survived to the modern era for us to scrutinize!

Now was it just chance or did they actually have something effective to them? There are a number of modern medicines derived from traditional practices[1], not to mentioned thousands of documented medicinal herbs that are understudied and difficult to cultivate (like the Monotropa Uniflora [2] for example). But we help ourselves little by fulling ignoring the possibility of their effectiveness. In any case, its not as if any of our medical practices we employ today does not have its source in traditional medicine, its just we can critically engage with those practices and attempt to develop something out of them with evidence-based trials. But a paradigm shift in thinking about medical practice won't happen if one always makes the same assumptions about what works and what makes people healthy. Examining these traditional/folk practices can help us do so.

[0]https://www.scielo.br/j/anp/a/rsfbjBsF9RFVgMz3DwzsnkC/?lang=... [1]https://pmc.ncbi.nlm.nih.gov/articles/PMC6273146/ [2]https://en.wikipedia.org/wiki/Monotropa_uniflora#Uses