Bit weird comparison. Like sure CephFS doesn't support S3-like access... because the object store is a separate service that also runs on top of Ceph/RADOS store
It is weird, but it's also a valid use case. I can imagine someone wanting to pull files from a FS that was populated as a regular POSIX filesystem through an S3 api. I'm not sure if you can access the CephFS files from the underlying Ceph store easily.
You could run Minio just like they do.
It's doable to run a MinIO gateway on top of CephFS mount point, but that will has performance issue, especially for multipart-upload and copy. That's why we put MinIO and JuiceFS client together and use some internal API to do zero-copy uploads.