If anything, I'd say a placebo probably helps a patient help themself.
Tell a depressed patient that you've got a pill that helps them think more positively, and you might trick them into cheering up a bit.
That said, depends on what form it takes. If they're just exhibiting demand characteristics 'cause they think they're meant to say they feel happier, then it's a waste of time, and just as importantly of the patient's hard-earned money. But if it helps, then why not give it a shot? It's not exactly dangerous, it's the kind of superstition everyone clings to. It's just like a comfort blanket. Everyone's got one in some form. No, the comfort blanket doesn't do anything. It just sits there. If you were attacked, the blanket would just sit there doing fuck all while you got your head bludgeoned. But if it gives you psychological strength, it's doing something! But I mean, it works everywhere. Not confined to superstition. How about how people feel safer in their own houses? Are they safer? Not especially. But it's a human impulse.
If you can craft the way a patient thinks, that's almost more powerful than medicine. It's like the old storybook cliche. "It was you all along." Giving a patient the power to feel better on their own terms is, in some ways, better than making them dependent on x chemical.
I think placebos have a place in medicine. It's a very small niche, and it's got to be done carefully, and it won't work on skeptics, and blah-de-blah-be-blah but when the planets align they can be golden.