If you want to have multi-host redundant storage at home (via e.g. minio or ceph), S3 is a pretty good protocol to provide it.
S3 is nice in the way it’s not a file system so it can have relaxed semantics, while also providing secure access to individual files over HTTPS via URL signing.
Some people seem to be stuck in the idea that S3 means cloud hosting. Not sure if that was your view, but it’s worth spelling out sometimes.