Short form video doesn’t work if not inside a manipulative application. Vine died because it wasn’t properly manipulating its users. The app literally gives you the tools needed to create the content that is appropriate for it to serve up and manipulate, and rewards those who develop more engaging methods.

You can create a short form video and post it pretty much anywhere, but it won’t work out well because it wouldn’t be inside the tool that is designed to use that content for its own purposes.

The app manifests the content.

The core of it is the algorithms and design. The content is the result.