I do use Docker for freezing dumpster fires like CSS toolkits that need to be built using node. And that works well to a certain extent, but there is still the complexity of Docker, having to set it up when you want to use the tool, having to deal with changes happening in it over the years, setting up filesystem sharing, etc.

Whereas with Perl it's easy: any UNIX system (and I do mean UNIX in a wide sense, as I've run perl on systems like HP-UX, Solaris, Unicos, IRIX and others) will normally have perl5 installed and you'll be able to just run your software. If it doesn't have perl5, installing it is usually very easy and you don't have to deal with horrors like the python2->python3 transition.