I don't understand why it matters for the conclusion whether lower cholesterol (or specifically LDL) is caused by diet or statins or something else altogether (

I don't understand why it matters for the conclusion whether lower cholesterol (or specifically LDL) is caused by diet or statins or something else altogether (if the assumption is that high LDL affects mortality). [Edit] I just read another one of your comments that answers my question, and I think you're right: https://news.ycombinator.com/item?id=20138685 https://news.ycombinator.com/item?id=20138685