S3 is not a filesystem replacement unfortunately.

Why not? It's a cloud service that stores files, can pretend to have directories, and for which there exist multiple utilities to mount the thing as a local file system. What's the shortcoming?

S3 is object storage not block storage.

https://www.digitalocean.com/community/tutorials/object-stor...

Object storage isn’t random access (the ability to read and write any part of a file) the way a disk drive is. This causes complications for software that expects to be able to randomly access a file like they would on a disk.

WebDAV is also an object storage protocol but it can do random access. Well, almost.

Partial reads are supported everywhere out of box just by using the Content-Range HTTP header.

Partial writes aren't standard, but some implementations e.g. SabreDAV can do those using PATCH with X-Update-Range header (and e.g. rclone supports this).

WebDAV has its warts and limitations but it's a very underappreciated protocol.

As someone else pointed out, it's object storage not block storage meaning things like partial reads and partial writes don't work. That may not be a problem for you, but it _is_ a problem for me (particularly when dealing with remote data).

> for which there exist multiple utilities to mount the thing as a local file system

Which all have their own sets of intricacies. The most obvious one being listing a directory is either impossible, costly, or as slow as the heat death of the universe. Other (far riskier) ones (from s3fs-fuse, which I have the most experience with[0] ) are the lack of guarantees about atomicity and concurrent access.

[0] https://github.com/s3fs-fuse/s3fs-fuse

Not a filesystem, but rclone works pretty well

rclone also works with Google drive, if that's all you're after.

Why pay when https://min.io/ exists?