> I too had thought it [OpenSSH] was key linux ssh infrastructure.

As a side note, OpenSSH is quite independent of the Linux ecosystem. It is developed as part of OpenBSD.

openssh-portable is provided as a standalone software package that is broadly POSIX-compliant.

No it’s a horrible fit. OpenSSH is focused on a high quality, secure implementation of a rather complex protocol. And OpenSSH is not a core piece of Linux infrastructure any more than say gcc is. These projects serve other, greater ends. A FUSE driver is a bunch of baggage that is poorly suited to be maintained with it.

I kinda doubt it, SSH already have SFTP and SSHFS is .... quite honestly a tool that has no business existing.

It's a neat trick but it's always going to be something that someone bolted on to a solution because they didn't want to deal with a proper file server. Part of the appeal might be that NFS (3 or 4, take your pick) is still the best we've been able to come up with and neither is really that great for basic installation. Still SSHFS is a mess to deal with in a production setup. Some of the messiest production systems I've de-tangled over years have frequently been relying on SSH and SSHFS to do stuff assumes a permanent connection.