Minified Javascript is pretty easy to turn back into something moderately understandable just by "prettifying" it. I do this all the time. It works pretty well because it started as Javascript, so turning it back into Javascript has a relatively clean mapping. WebAssembly will have started as some other language or even as no language at all - there may be no mapping back to anything Javascript could represent. It will be much closer to disassembly of machine code, or Java byte code, which is possible but challenging enough that most ordinary developers never do it.