Write-only perhaps, but with perl you only have to write it once and it'll run forever, anywhere. No breaking on updates, no containers, no special version of Perl just for $application, just the system perl.
Because of this, in practice, the amount of system administration mantainence and care needed for perl programs is far, far less than other languages like python where you actually do have to go in and re-write it all the time due to dep hell and rapid changes/improvements to the language. For corporate application use cases these re-writes are happening anyway all the time so it doesn't matter. But for system administration it's a significant difference.
Agreed! My father (RIP) absolutely loved Perl and could do amazing things with it in seemingly impossibly-few characters. I got reasonably proficient w/ regex but never came close to his wizardry. Much respect for those in his rarified company.
Pure perl modules are not, unless they use syntactic features that first appear in the newer versions.
Modules with C extensions have to be recompiled with libperl they run against, as much as CPython extensions link to a particular libpython, and guess Ruby is the same. But they, with very few exceptions, will recompile and run fine. XS is cryptic but its backwards compatibility story is good.