This was solved in the same way that assembly languages are touring complete. It's true, but it's not useful. You need a compiler to output those meaningless numbers. What happens when you install something after booting? Who starts it? On a long running system those files are useless. Which ones have you run? Are they idempotent? Systemd attempts to solve all of these problems and more.

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.