The concept of 'fair use' does not magically give you permission to use other people's creative expressions on your own platform. Moreover, the concept of 'fair use' does exist in the United States, but not everywhere else in the world.
To clarify: copying other people's content and calling it 'fair use' without explanation and permission is not permitted. In the United States, a number of important conditions are imposed on content before it can be copied by third parties under the concept of 'fair use'.
Before you decide to use third party content covered by the 'fair use' concept on your own video platform, we recommend that you first carefully consider the consequences of that decision. A lawyer may be able to tell you what is and what is not allowed under local law.