EDIT: Let’s cool it with the downvotes, dudes. We’re not out to cut funding to your black hole detection chamber or revoke the degrees of chiropractors just because a couple of us don’t believe in it, okay? Chill out, participate with the prompt and continue with having a nice day. I’m sure almost everybody has something to add.
Because we’ve decided it’s nonethical for healthcare professionals. Any doctor knowingly prescribing placebo and lying about it could get in some major trouble. Like a couple decades ago I heard a psychiatrist mourn the loss of disulfiram (antabuse) implants from their treatment arsenal; it worked very well as a placebo but research didn’t show a clear improvement over placebo, so they could no longer use it.
I am kind of glad that non-license-needing wellness consultants can still use the placebo effect for good, even if it is sometimes predatory and sometimes outright dangerous.