Much like C, which also requires floating point support. WebAssembly implementations for tiny IoT environments can emulate floating point in reliance on people not using it heavily, just as you'd expect them not to run Node.js. But at least the developer has the option, which can have significant value, such as during exploration and experimentation phases.

Similarly, compilers like GCC will synthesize 64-bit arithmetic inline for i386 and other targets lacking 64-bit support. These days few people think twice about using 64-bit data types even though 32-bit processors are still in heavy use. (Though, AFAIU emulation has largely moved from compiler to the instruction decoder or microcode.)