I think the real interesting value in putting an RDBMS underneath the filesystem would come from relationally modeling the objects in the filesystem, ie files a

I think the real interesting value in putting an RDBMS underneath the filesystem would come from relationally modeling the objects in the filesystem, ie files and types and their contents, and then being able to query those things with SQL. If their relational schema is just inodes and blocks I don’t really see the value - after all the filesystem is just a miniature RDBMS purpose-built and optimized for that fixed schema and so it’s not surprising that their system is so much slower.