It is easy to make benchmarks where JS is faster. JS inlines at runtime, while wasm typically does not, so if you have code where the wasm toolchain makes a poor inlining decision at compile time, then JS can easily win.

But that is really only common in small computational kernels. If you take a large, complex application like Adobe Photoshop or a Unity game, wasm will be far closer to native speed, because its compilation and optimization approach is much closer to native builds (types known ahead of time, no heavy dependency on tiering and recompilation, etc.).