An eye opener for me was when a friend of my was dying of cancer there was a period where he got sepsis, ultimately because of the effects of chemotherapy not directly because of the cancer. But had he passed from sepsis (he survived that incident), the cause of death would ultimately be attributed to cancer and not chemotherapy.

I looked into it deeper at the time and it's very difficult to untangle the true cause of death in many of these situations. While certainly these treatments are ultimately beneficial statistically, it is concerning that there's not as much discussion around their harm and the real risk rewards behind various treatments. I know from my own (non-cancer) experience that there is a very strong bias towards treatment even in cases where, once you break down all the risk and rewards, there is a strong argument for non-intervention.