Perl and Matlab? Seriously?
Often in places like automation, or gluing disparate systems together.
While I know the TIOBE index has its flaws, Perl is consistently in the top 10 and has maintained that level of popularity for 20+ years.
With a history like that many critical systems are going to have a Perl dependency somewhere which means companies are going to need Perl developers.
That said, Perl openings do seem to be in serious decline. Right now on indeed.com, there are 700 openings mentioning Perl for the BA. There are 4000 Python openings.