Earlier quoted context omitted.
If placebo’s didn’t have clinical effects we wouldn’t be controlling for them in every scientific study
The entire premise of a placebo-controlled study is to see if a treatment works better than something that produces no effect.
Whereas, comparing a treatment straight to non-treatment, leaves it unclear how much of any perceived benefit the treatment has was due to placebo, or the specific treatment.
You may have been saying that, I wasn't sure what "no effect" was emphasizing.
An alternate means of getting the same comparison is to have treatment and non-treatment applied without any patient knowledge of either, when that can be done. Which works, and is more straight forward from a measurement standpoint, but is ethically unacceptable.