The process model is a sandbox. Every process runs as if alone, with seemingly continuous processor time and memory addresses starting at zero. The ailments you described are all system calls, special access granted by the kernel.

So the process model is not fundamentally different than the browser model, but WebAssembly enjoys two advantages:

1. The browser security model sagely segmented privileges by origin rather than user.

2. Like bytecode, WebAssembly AST does not target a specific processor.