From Edward Tufte’s book “Data Analysis for Politics and Policy”:

“One day when I was a junior medical student, a very important Boston surgeon visited the school and delivered a great treatise on a large number of patients who had undergone successful operations for vascular reconstruction. At the end of the lecture, a young student at the back of the room timidly asked, “Do you have any controls?” Well, the great surgeon drew himself up to his full height, hit the desk, and said, “Do you mean did I not operate on half of the patients?” The hall grew very quiet then. The voice at the back of the room very hesitantly replied, “Yes, that’s what I had in mind.” Then the visitor’s fist really came down as he thundered, “Of course not. That would have doomed half of them to their death.” It was quiet then, and one could scarcely hear the small voice ask, “Which half?””

https://www.edwardtufte.com/tufte/dapp/DAPP1.pdf

(further attributed to Dr. E. E. Peacock, Jr, as quoted in Medical World News, September 1, 1972, p. 45)

In clinical trials, pure placebos are very rarely used (only in mild conditions or where no treatment exists). Commonly novel therapies are compared against the current treatment of choice.

I was about to ask how ethical it could be to give a pure placebo in cases as serious as heart failure, when simply telling the patient (or the patient's family) that they received some other more conventional procedure should produce similar results.

I think this is never done. I suppose both groups receive two therapies, one of them being the best available therapy for the condition, and the other either the new therapy, or a placebo.

This requires new and old therapies to be compatible, though.

Studies will also be suspended if it becomes clear that one treatment is so obviously better as to be unethical to continue with the other.

You would rather not sign up and go for the 100% percent chance they give you nothing and you die?

Maybe in those cases, if the treatment, if it shows promise, should be given also to the people that were given placebo (after the study)

I'm very excited about this stuff ... but as a relatively healthy person, I'm gonna wait for v1.1 :)

At that point it's far from certain that the medicine will give you higher chances of survival though.