There is SO MUCH CODE out there. To some degree that is a bad thing, but there are genuinely good libraries in other languages that would be nice to more seamlessly utilize in other languages.
Generally, there isn't a "best of breed" movement to actively track which implementations and approaches to things (json deserialization/serialization, http client, regular expressions, high speed I/O, algorithms and data structures.
Instead, good approaches organically move around, or are at the whim of the steward of a language recognizing and pushing for some new language, approach, etc. Often good approaches or libraries or interfaces are shut out from another ecosystem over nothing more than dogma or reactionary hated in the worst case.
Instead, if one language gets a good library, you either interface at the OS level or you have to migrate to that language if the library is that critical.
The JVM was close to this, with Jython, JRuby, Javascript, Groovy, Clojure, and lots of other languages runnable within JVM code. Ultimately, notably Ruby where the JVM was the fastest runtime for Ruby for a time, rejected that approach.
But I think it was the right approach fundamentally, if the politics got in the way. LLVM may have that potential, but it seems to tied to compilerland. OS-level interop seems generally a failure, either because of OS balkanization or other concerns.