[DanielHB]

In my experience WASM performance is not that much better than JS in most cases, not so much because WASM is lacking, but because most JS runtimes performance is really, really good for a dynamic language.

When I measured C compiled with clang -O3 vs JS performance the only noteworthy speedup were on math-heavy tasks and even there only for integer-heavy math (floating point math was better than JS, but not by much). In a few cases the performance was worse. Notably recursive algorithms were _much_ better in WASM though even with algorithms that can't have tail-call optimisation (I guess function invocation has a lot of overhead in JS compared to C)

I think people over-value WASM speed. With regards to performance I imagine that the biggest gains compared to JS would be from not using garbage collection language. GC overhead, especially JS GC (compared to golang GC) can be painful in very large applications, especially in things were timings matter like 3d rendering. But GC can be optimised for in JS by avoiding allocations in the critical paths of the app