We have a long on running research project with the intention of carting a "libpglite" with a C FFI and compiled as a dynamic library for native embedding. We're making steady progress towards it.

There are projects such as https://github.com/wasmerio/wasmer-java and https://wasmtime.dev/ that extend this embeddability to Java, .net, C, C++, rust, Python, Ruby and Go. Wouldn't want to call those 'JS et al'.

Ofcourse, that ignores the fact that for many of these languages there are existing libraries and drivers to connect to databases that would not work with this embedded one, but still.