RSpec makes coding an app feel more like writing a book.

expect { User }.to have_attributes(:name) 
expect { Counter.increment }.to change { Thing.count }.by(1)

As a fan of domain-driven design, I like tools that give you a more specific language that fits what I'm doing: test-driven development.

Tools like MiniTest & Test::Unit often feel like a mix of readable code, and symbol-heavy code. You'll see raw ruby code: function definitions or class definitions, which require more cognitive complexity to understand what's going on.

RSpec, on the other hand, could be read by anyone, even non-technical people. MiniTest & Test::Unit especially become less readable when you consider the popularity of RSpec, and all the extensions such as GraphQL, ActiveRecord, etc.

Once you master RSpec (it's super easy & worth doing), it's easy to spend 80% of your development on specs, & have specs that are as lengthy as your code, because tests are very easy to write.

That doesn't mean they'll pass, though! :)

I highly recommend using RSpec to write your own matchers in your "domain-specific language" (DSL). If you're doing tests for an app that uses machine learning to detect images of pancakes, you'd want a custom matcher like:

subject { Pancake.new(flat: true)  }
it { should be flat }
it { should have_toppings(:syrup) }

Checkout an example of a custom matcher I made that checks object types to avoid security risks or bugs:

https://github.com/patrickclery/rspec-dry-types