This is the same execution model real embedded interpreters like wasm3 use to run WebAssembly on microcontrollers with no JIT available, and it's the fallback tier every production engine (V8, Wasmtime) has before a function gets compiled. Getting local.get/local.set and the implicit operand stack right here is the prerequisite for the JIT task later in this subtrack, which just replaces this same dispatch loop with native code generation.