It's not like strong typing came after Ruby. In fact, duck typing was a _feature_ of Ruby on its days. At the end of the day, you choose your battles, it's not a black-or-white decision.
No, but gradual/optional typing did come after Ruby. Back in 2005, you could choose between static typing with type checking but lots of verbosity (e.g. Java "Point point = new Point();" or C++ "for (std::map::iterator it = myMap.begin(); it != myMap.end(); it++)") or dynamic typing without type checking but also without the verbosity. Since optional typing, dynamically typed languages got the guarantees of type checking, and JavaScript/TypeScript and Python have embraced this. With type inferencing, statically typed languages lose their verbosity, and Java and C++ have embraced that (as have newer languages like Rust, Go, and Swift). It feels like Ruby hasn't progressed on this front...