That isn’t (currently) a goal of WebAssembly:

https://webassembly.org/docs/faq/

“Is WebAssembly trying to replace JavaScript?

No! WebAssembly is designed to be a complement to, not replacement of, JavaScript. While WebAssembly will, over time, allow many languages to be compiled to the Web, JavaScript has an incredible amount of momentum and will remain the single, privileged (as described above) dynamic language of the Web.”