>>todsac+(OP)
Perl's "decline" saved it from a fate worst than death: popularity and splitting into dozens of incompatible versions from added/removed features (like python). Instead Perl is just available everywhere in the same stable form. Scripts always can just use the system perl interpreter. And most of the time a script written in $currentyear can run just as well on a perl system interpreter from 2 decades ago (and vice versa). It is the perfect language for system adminstration and personal use. Even if it isn't for machine learning and those kinds of bleeding edge things that need constant major changes. There are trade-offs.
This kind of ubiquitous availablility (from early popularity) combined with the huge drop-off in popularity due to raku/etc, lead to a unique and very valuable situation unmatched by any other comparable language. Perl just works everywhere. No containers, no dep hell, no specific versions of the language needed. Perl is Perl and it does what it always has reliably.
I love it. The decline was a savior.