But the point is that the tooling to do this is non-obvious. The same issue exists for all these kinds of archives— container image layers, ISOs, VMDKs, deboots

But the point is that the tooling to do this is non-obvious. The same issue exists for all these kinds of archives— container image layers, ISOs, VMDKs, debootstrap outputs, etc. All of them are things that should be possible to just emit directly into a user-owned archive, but often require mounts, overlays, chown, and who knows what else. Another related one is about installing grub into an archived filesystem or disk image. Should be trivial, right? But most instructions for this require mounting it, which immediately means you need SYS_ADMIN and therefore a privileged container in your CI setup.