ALL of that goes through cpanel, for every shared hosting provider I can ever remember using. Even if the stuff happening on those servers didn't use perl, cpanel itself -- the admin of everything provided for that domain by the hosting provider -- it's a huge surface area.
I understand how they work, I'm familiar with HTML::Template, and related modules, so I can hack up a quick interactive/dynamic site in a couple of hours.
They're no longer things I'd run on the public internet, but for quick internal things it's very easy to deploy a container with a perl backend.