I don't dislike JS but the reason why it's fast is because billions were poured into making that happen.
V8 is a modern engineering marvel.
And WASM hasn't been around for as long, so WASM implementations are not as mature.
There is no reason why WASM couldn't be as fast, or faster than JS, especially now with WASM 3.0. Before, every programs in a managed language had to be shipped with its own GC and exception handling framework in WASM which was probably crippled by size constraints.
Yeah, and like many engineering marvels, it was instantly misused for purposes its creators didn't intend and became a scourge on humanity (looking at you NodeJS & co).