The guy way overused "deprecated" in that article.
Perl 5 is alive and well, and while not the most actively developed of languages still has a steady trickle of small improvements.
It's installable in all major linux distros and you can probably get code from 2 decades ago running without much hassle.
Most people would shudder at the thought of starting a new project in it, but if you need to keep a legacy codebase going the community have your back for many many years to come.