I don’t get why docker doesn’t include a simple command (docker backup volumexyz mybackup.tar.gz) that creates an archive from a volume. Why do I have to do tha

I don’t get why docker doesn’t include a simple command (docker backup volumexyz mybackup.tar.gz) that creates an archive from a volume. Why do I have to do that myself by mounting the volume in a second container? Ok, there might be volumes that can’t be backed up (mounted sockets for example), but that could just give an error message.