I cannot count the times that I've been asked the question "If too many people learn supply and demand trading rules, will it stop working?". The simple answer is absolutely not but let's look at a few of the many reasons.
Each individual trader is unique and has their own personality of trading. Some may trade very short-term and others may prefer to hold their trades. While both of these individuals may be using similar rules for supply and demand trading, their orders will almost always be different because of the data they are analyzing.