In general, I think the significant improvement in Speed in case of WebAssembly binaries will be largely due to SIMD support. But performance gap between JS and

In general, I think the significant improvement in Speed in case of WebAssembly binaries will be largely due to SIMD support. But performance gap between JS and WebAssembly is not at all deciding factor unless you are creating a high quality Games. There are lot of online games with low to medium graphics quality created using 2D canvas or 2D/3D WebGL libraries which run just fine on modern web browsers. Most developers, at least in my experience see just plain Array and JSON. If they get themselves familiar with API like WeakRef (WeakSet/WeakMap), ArrayBuffer along with DataView and Various Typed Arrays (Int8, Int16, Int32, Uint8,Uint16,Uint32, Uint8Clamped and likewise for Float and BigInt) they can write Garbage heap friendly and more computation focused code. Besides that, strictly speaking for standard web application development, JS ecosystem of libraries and frameworks are miles ahead for handling various kinds of UX/UI journey scenarios. Developer tools in the browser to do various kinds of performance inspection and profiling of the JS code. I wonder why JS engines (like V8 for example) rely highly on Scalar instructions ? There is lot of scope to apply auto-vectorization and generate SSE, AVX, NEON (for ARM) instructions. If they implement this or at least provide some API like SIMD.js (one they abandoned in the past), it will make WebAssembly close to redundant unless you hate JS or other PLs which transpiles to JS.