Interoperability is about practicality and performance cost. I think Swift is quite practical and efficient in this regard - from day 1 it has near-zero C-lang integration costs, and now it has C++ support.

Also, https://github.com/swiftwasm shows how the modularity pays off. Comparing it to the other languages that got stuck with incompatible frame conversion (Golang) or JIT memory management problems (JVM) it's not bad at all.