Yeah I do think there is a performance bottleneck here with WASM being quite a bit slower than native performance. But I think the idea is that WASM performance is only going to get better as the technology keeps evolving, and that gap will be bridged.

I'd say the overall performance of the tool itself is a bit mixed. There are some task where it performances really well (trimming, converting photos to montage) but some where it is horrible(transcoding to VP9)