CPAN definitely deserves more attention, especially for the emphasis on testing which many successors still don't have. That was even more necessary back when OS consistency was worse but it really should have been seen as a first-class feature.
I think C/C++ also had this problem with the whole cultural evolution around shared libraries. Because installs were non-trivial I think there was an almost subconscious blinder effect where people restricted themselves to what shipped with the OS / distribution even if that meant keeping a workaround for a bug which had been fixed upstream years before because that was seen as better than static linking or bundling a newer version.
the pedantry around design and testing in CPAN is where i learned how to be a serious software engineer. perl was special in that it bridged the divide between software engineering and system administration. it was software engineering with the pedantic nature of high strung sysadmins who insisted the garden was in perfect shape at all times.
I think C/C++ also had this problem with the whole cultural evolution around shared libraries. Because installs were non-trivial I think there was an almost subconscious blinder effect where people restricted themselves to what shipped with the OS / distribution even if that meant keeping a workaround for a bug which had been fixed upstream years before because that was seen as better than static linking or bundling a newer version.