The current iteration of WebAssembly was always an "MVP." It's got the core instruction set and memory model to run, essentially, C programs safely and efficiently, and just enough interop with the host to get data in and out.
But it was always the plan to expand on that, and make a wider set of use cases easier and more efficient. Working directly with the DOM really requires some amount of integration with the GC that manages the DOM, for example.
The thing that makes this interesting outside the browser is the security model. Unlike typical environments used for FaaS or whatever else, it's capability based and starts from literally zero- everything a WebAssembly module can touch has to be passed in explicitly when it's instantiated. That's a lot narrower, lighter weight, and more flexible than things like containers.
But it was always the plan to expand on that, and make a wider set of use cases easier and more efficient. Working directly with the DOM really requires some amount of integration with the GC that manages the DOM, for example.
The thing that makes this interesting outside the browser is the security model. Unlike typical environments used for FaaS or whatever else, it's capability based and starts from literally zero- everything a WebAssembly module can touch has to be passed in explicitly when it's instantiated. That's a lot narrower, lighter weight, and more flexible than things like containers.