If there was such a direct and effective identification method, the counterfeiters would have done it long ago, otherwise the level of fraud would be almost the same.

There is no such "most direct and effective" identification method.

When distinguishing the authenticity of any product, we need to make a comprehensive judgment from external packaging, various identification information, internal electrical wiring status, processing details and so on. Many times, only people who are very familiar with this kind of products or the products of this manufacturer can do it.