Its been almost two decades, but I remember clicking on links in perlpod manpages ... I think using bin/info ...

Heh, yeah, but those are "hacks" in the viewers, as also explained in the linked answer:

[…] most pages aren't really designed for hypertext, and the default man program doesn't support it […]

There are however man page viewing programs that reconstruct some hyperlinks […]

My point was just that the underlying language doesn't support hyperlinks and, as such, a generator needn't check the validity of links. This is probably different for formats like Texinfo (or, more prominently, (X)HTML), which do understand and use the concept of hyperlinks.