Yes. Wasm does to my knowledge not have an answer for this, even if some projects patch in their bridge logics. Networking and file systems, and the permission model, is "the rest of the fucking owl". Linux isn't standardized, but at least it's Linux. Without consensus on the fundamental APIs I don't see how we can get to a platform agnostic experience. Even an https call isn't simple: you need TCP and you need to pull root certs from the env, at the very least. Where's the API for that?
I hope for a much more near term bright future for WASM: language interop. The lowest common denominator today is C, and doing FFI manually is stone age. If you can leverage WASM for the FFI boundary, perhaps we can build cross language applications that can enjoy the strengths of all libraries, not just those outside of our language silos.