There was a short time window in browsers where WASM was actually AOT compiled, instead of the tiered compilation model that seems to be common now. I actually preferred the AOT compilation because it meant that there was no JS-like warmup phase until the code reaches full speed. This was a problem for large WASM blobs though because compilation took too long, and instead of "encouraging" people to write small WASM blobs, the browser makers "caved in" and moved towards a more JIT-like model (first pass is "compile fast but run slowly", and then compile hot functions with an optimizing compiler again).