I've written about limitations of WebAssembly https://qouteall.fun/qouteall-blog/2025/WebAsembly%20Limitat...

WebAssembly still doesn't provide a way to release memory back to browser (unless using Wasm GC). The linear memory can only grow.

The Wasm GC limits memory layout and doesn't yet support multi-threading.

Wasm multithreading has many limitations. Such as cannot block on main thread, cannot share function table, etc. And web worker has "impedance mismatch" between native threads.

And tooling is also immature (debugging requires print debugging)