Yea, Perl thrived while there was no real alternative.

PHP arrived and ate into it's web app use-cases. Modperl wasn't great for hosted environments, to say the least.

Python matured and started eating into it's systems use-cases and eventually the web use-cases as well. And was just so much easier to work with and learn.

Perl was left with no real niche where it really shined, except one-liners and making poetry I guess