We're using Perl for a new startup. Our team has a background in computational biology where Perl is still big. Some of us have more than 10 years of Perl experience and if you know the language well it's just insanely productive.

Readability was never an issue. We follow a few common guidelines and with Perl::Tidy we get consistently formatted code.

So in principle Perl is perfect for us, the only drawback is that there is less and less library support for Perl. Most services like for example Stripe have libraries for Python, Ruby but don't bother with Perl (and I don't blame them). Third party libraries from CPAN are usually not that robust and well maintained.

But in general the Perl backend is the most robust part in our codebase and I would not trade it for any other language.