Well, as complex as Nix+whatever-you-have-cobbled-together-to-build-and-editor-instrument-ghcjs is, it pales in comparison to the sheer ferocious confusion granted to the ecosystem by tools like webpack, so I can see where it might seem like an improvement in some regards.
Webpack: it's like lens error messages for your builds, at runtime!
Everyone has different priorities. I know some users who started using Haskell at all with reflex-platform despite the difficulty because it scratched exactly their itch.