"Look up the source" in 2024 is a symptom of a wider problem. Ruby was innovative in the 1990s but it is starting to fall behind the times.
Those of us who are old enough to remember the euphoria that greeted the release of Ruby on Rails in 2004 are mostly surprised to see Ruby's current, limited market share. There was a moment when it seemed like Ruby was going to sweep the whole world of software. But that didn't happen. The mutability that made Ruby so fun also makes it difficult to maintain Ruby codebases over the long-term.
For awhile Ruby seemed relevant in fields beyond Web development, such as devops. I recall 12 years ago a startup tried to recruit me, they were going to revolutionize devops by building automations for Chef. But the metaprogramming in Ruby made it less than ideal for devops work. That startup failed. In most places I now work, a combination of Ansible and Terraform dominate, save where the company uses the constellation of tools surrounding Kubernetes to manage everything. The places that use Chef have been using Chef for 15 years, no new company chooses Chef today.
There was a stretch after 2004 when Ruby was trying to break into new areas. GTK bindings for Ruby were developed and some people experimented with desktop Ruby. But that never took off.
Many of us who loved the metaprogramming in Ruby, but wanted a better structure for that metaprogramming, moved on to other languages such as Clojure.
Some of us loved Ruby because it allowed easier polymorphism than Java did -- after all, you could use higher order functions to produce functions, but without having all the ceremony of building a Factory. But folks who just wanted the polymorphism of functions returning functions eventually moved to NodeJS.
Ruby always felt fluid and magical in a way that made it seem vaguely unsuitable for data science, and eventually Python came to dominate data science.
The Ruby community witnessed the conflict between Rails and Merb, and their eventual union, and eventually Rails became a comfortable framework for quickly generating an API. But for anything that needs high levels of write throughput, no one would chose Ruby, and so other languages have taken some of the market share.
Even on the Web, some big companies (Twitter, AirBnB) either gave up on it completely, or now only use it for templating the frontend, or offering an API to support the frontend. For backend processing, many companies have moved away from it.
In short, Ruby has been losing market share for awhile. In some fields, such as devops, where it used to be competitive, it has almost completely disappeared. It survives only in Web development, and only because of Rails.
None of this can be very inspiring for Ruby developers.