These codes aren't talking HTTP. They are talking POSIX to a real filesystem. The problem is that cloud-based FUSE mounts are never as reliable (they will "just hang" at random times and you need some sort of external timeout to kill the process and restart the job and possible the host) as a real filesystem (either a local POSIX one or NFS or SMB).

I've used all the main FUSE cloud FS (gcsfuse, s3-fuse, rclone, etc) and they all end up falling over in prod.

I think a better approach would be to port all the important science codes to work with file formats like parquet and use user-space access libraries linked into the application, and both the access library and the user code handle errors robustly. This is how systems like mapreduce work, and in my experience they work far more reliably than FUSE-mounts when dealing with 10s to 100s of TBs.