Most claims that a treatment will make you 100% better or that it works for everyone turn out to be wrong.
The effects of some treatments are obvious. For example, it is obvious that not putting your hand in a fire is a good way to avoid burning it. However, the effects of most treatments are not that obvious. That is why we need fair comparisons.
REMEMBER: Few treatments have such obvious effects that we do not need fair comparisons to know how helpful they are.