> seems like the treatement is almost worse than the disease.

I think that's what the poster above you was saying. "Oldschool" chemo is basically poison, and the hope is that it kills off the cancer before the patient. But there are newer drugs that are extremely effective with way way way less side effects out there, depending on which type of cancer one has. Things like immunotherapy are really effective if you happen to match their targeted types of cancer, and some have basically 0 side effects, leading to a QoL improvement if they happen to work. People have gotten nobel prizes for some of these discoveries, it's really insane how far we've come in the last 30-40 years.