There even have been several blinded trials, that were discontinued mid-way, because the drugs being tested were so effective.

To continue giving placebo and denying obvious cure would be unethical, and so the trial was stopped, placebo arm cancelled - and everyone got the actual medicine.

in the “just try it and see scenario”, you offer it as a possibility, and everyone who ops in, gets it.

it might not be as scientifically rigorous, but that's a big difference to the patient who suffers from receiving a placebo instead of the real deal