Which part of this benefits from blockchain? Suppose an alternative implementation where a media file contains a signed certificate of creatorship that can inc

Which part of this benefits from blockchain? Suppose an alternative implementation where a media file contains a signed certificate of creatorship that can include other certificates (so your can cut would have a certificate signed by you, including as a payload the original certificate signed by the original creator). I can immediately see several attacks on this system, but I don't see an attack that blockchain would solve. For example, the fan cut could just not include the original creator's certificate. I don't see how a blockchain would help in uncovering this. Maybe if the blockchain contains the full video files? Then you could use regular plagiarism detection software or ContentID-type systems to find possible rights violations. But then the blockchain size would quickly balloon beyond the point of usefulness, and also it's not substantially different from just putting all the involved media on public web servers for people to mirror.