I like the idea of using the same format for kernel-included VMs as I use for containers.
Next up, backups stored as layers in the same OCI registries.
I am not, however, sure ostree is going to be the final image format. Last time I looked work was in progress to replace that.
It is not, the future is currently pointing to composefs:
https://github.com/bootc-dev/bootc/issues/1190
There's a GitHub org that builds bootc-ready images for non-Red Hat family distributions using this backend.
https://github.com/bootcrew