The page I linked lists quite a uses cases that would become possible/easier with a new protocol. To your specific concerns, object storage systems like S3 don

The page I linked lists quite a uses cases that would become possible/easier with a new protocol. To your specific concerns, object storage systems like S3 don't support partial writes to files, which makes FUSE mounts a leaky abstraction. SSHFS is much better, but obviously can't be used in web apps. I'm not saying we need to replace existing protocols, but we need one that can work in a more diverse set of use cases.