What do you mean by "powerful". Meaning you can type less code. You can still do delegation by writing it out yourself. Or you can also use the Delegator or Forwardable classes to save some typing. I'm not sure what meta programming they use under the hood. Probably define_method or method_missing.

Also, people always forget to throw NotImplemented errors which can lead to some fun to track down bugs if you make a typo sending a message. Which I guess is why you pretty much have to write tests for everything in ruby. This kind of stuff would be caught by a compiler in other languages.

Disclaimer: I don't buy into the idea of "message passing" or a lot of OOP. They're the microservices of programming languages.