Don't those correspond to runlevels? I can boot to runlevel 5 and not have all file systems present and working e.g. an NFS filesytem might not be available. S

Don't those correspond to runlevels? I can boot to runlevel 5 and not have all file systems present and working e.g. an NFS filesytem might not be available. So I would say it has been hacked around for decades. Not cleanly solved. But I am not the best informed here so please add more details about how numbered init symlinks guarantee file system being there before a service is started.