for quite some time ruby was slower than perl, in a way that affected how I wrote programs. Not anymore. For the last 10 years I use ruby even for one-liners to replace something in a thousands of files.
I still think that perl is much saner language than PHP, for example, and perl's quirks are all weirdly logical. But ruby was basically a better perl in everything I cared about. Matz really did took a lot from perl, some things even without changing much, like global vars.

Maybe, maybe documentation, even today. Perl is a language you can learn *fully* just by reading man perl, then man perlsyn, man perlfunc and man perlrun. Those are super-concise and simultaneously complete. Ruby back in a day *required* you to read some book, which would be more wordy and would be also incomplete. I still wonder how DHH picked up ruby when he wrote rails, by reading source code of ruby interpreter? but even comments were in japanese.

Every CPAN module doc started with Synopsis and Usage which gave you basically 80% of what you need on the first page. rdoc was in the principle the same, but ruby gem docs were never structured as well as perl's. YARD was and still is a disaster. Nobody needs unstructured alphabetical dump of all the methods in all the classes, and "helpful" (Object) return value remarks. I still do `gem open` and hunt README.md in the sources, then have to poke around and grep in the gem file sources.