The thing is, sophisticated interfacing, GC, and multithreading - assuming they're developed and deployed in a particular way - only apply in the cases where you're applying it to use cases that need those things. The core compute abstraction is still there and doesn't diminish in value.
I'm personally a bit skeptical of the approach to GC that's being taken in the official spec. It's very design-heavy and tries to bring in a structured heap model. When I was originally thinking of how GC would be approached on wasm, I imagined that it would be a few small hooks to allow the wasm runtime to track rooted pointers on the heap, and then some API to extract them when the VM decides to collect. The rest can be implemented "in userspace" as it were.
But that's the nice thing about wasm. The "roots-tracker" API can be built on plain wasm just fine. Or you can write your VM to use a shadow stack and handle everything internally.
The bigger issue isn't GC, but the ability to generate and inject wasm code that links into the existing program across efficient call paths - needed for efficient JIT compilation. That's harder to expose as a simple API because it involves introducing new control flow linkages to existing code.
I'm personally a bit skeptical of the approach to GC that's being taken in the official spec. It's very design-heavy and tries to bring in a structured heap model. When I was originally thinking of how GC would be approached on wasm, I imagined that it would be a few small hooks to allow the wasm runtime to track rooted pointers on the heap, and then some API to extract them when the VM decides to collect. The rest can be implemented "in userspace" as it were.
But that's the nice thing about wasm. The "roots-tracker" API can be built on plain wasm just fine. Or you can write your VM to use a shadow stack and handle everything internally.
The bigger issue isn't GC, but the ability to generate and inject wasm code that links into the existing program across efficient call paths - needed for efficient JIT compilation. That's harder to expose as a simple API because it involves introducing new control flow linkages to existing code.