GraalVM truly has the potential to become the universal, interoperable VM. It would be rational for e.g Julia folks to migrate to the graalVM ecosystem and cotntribute to it instead of living on their small code island. They would get an un inimaginable amount of benefits in the process.
How does a VM (JVM, GraalVM) compare to something like LLVM's IR? From your description as a ``universal, _interoperable_ VM`` it seems like they have some similar goals --- what are the reasons to write a compiler to a VM instead of with LLVM/IR?
Llvm IR however has not been designed with inter language interoperability in mind or at least not enough. E.g rust has no transparant, complete, seamless and efficient interop with swift, go, c++, etc
But in theory llvm is just an AOT and both AOT and JIT can enable true interoperability which is why graalvm support both a jit mode and an AOT mode. However JITs enable better performance at least for any high level, GCed language than would an AOT.
Moreover, GraalVM through the truffle framework enable unprecedented language designer productivity. Through high level constructs the designers can be much more productive than in standard VM/AOT, which explains how with a few engineers Oracle has managed to reimplement Java, ruby, python, js and R in parallel in only a few years...