What do you think about this way of validating ideas?

Hello everyone. Recently, I have seen on the internet that one of the most important steps before starting a business is to validate the idea. I saw that one way to do this is to create a web page in which it appears that the product is already finished and all its features are mentioned, but when users click on "Get" a screen appears that says that the product is in development and enter your email if you want to be notified when it is finished. The idea of this is to know if the problem really exists and at the same time have a small base of potential customers. What do you think? Do you have any recommendations or suggestions?