It's true that in the beginning (around 2017), WASM wasn't much faster than asm.js, but meanwhile WASM has seen real performance improvements.
Featurewise, asm.js is much closer to WASM than to regular JS, it definitely cannot do everything that regular JS can do (mainly because asm.js is limited to the Number type, it cannot deal with JS strings or objects).
I don't think Chrome ever did an asm.js specific optimization.
We still need to download half Internet for emscripten, plus whatever tools are being used on top. Although it is somewhat simpler for those that build on top of binaren.
The next big feature coming is stack switching. It works best with unboxed continuations, which necessitates a fat pointer representation in the engine. Once the engine supports fat pointers, then interior pointers will be an easier sell. It might take several years to get there, but Wasm evolves slowly and deliberately, and IMO hasn't made any massive fatal design errors yet.