But it is useless, is it not? The placebo effect is effective, cheap and safe. If the new drug has the same effectiveness, it's probably just another placebo, just far more expensive and probably nowhere near as safe.
In real world scenarios however drugs might be bought with _no_ personal interaction with professionals at all. Furthermore people are very sceptical of the long-term effects of any psychology related drug. In this case the placebo's might perform a lot worse than the actual drug, which may have an actual noticeable effect.
The placebo effect is effective, cheap and safe, and might be present in both the placebo and the tested drug. But the placebo can't be sold as medicine. And the tested drug might still work without the placebo effect.
Especially in terms of psychological effecting drugs
If the people getting the placebo get better (in the case of psychological drugs.. feel better) as often as those on the actual drug, then it's quite likely the drug is doing nothing and both sets of patients are getting better because the belief of taking a drug that makes them better is causing them to get better.
(apologizes for the confusing paragraph)
And hence, the drug is deemed worthless and thrown out, time to get on with a trial of another drug.
The only way to be sure that the drug is doing nothing is to repress the placebo effect as much as possible.
There are people dying or suffering that could be helped with drugs that failed the placebo test. (Some of them could even have been helped with the placebos themselves)
In the real world enrollment to medical schools is heavily throttled and doctors in cities have many more patients then they can cope with.
There might be enough psychiatrists and other therapists, but they are not believed to be able to cure physical pain (even though they are), which renders them less effective. This is why these therapists rely so much on these medications that seem to have little effect over placebos.