Even if somebody did do all of this, merging the file from the app into a real project would be difficult. There'd have to be rules about merging, and diffing, and command line tools, etc. Maintaining and documenting all of this would be an absolute nightmare. And that's not even getting into engineering or marketing difficulties because you'll have people confused about the product identity, or say that it's too complex, or that it's buggy because it has so many more features now. And all this for pretty much nothing.
Because figma already has css exports (even if it's iffy, they're working on it). You export the styles, the padding, the colors, and that's what people really want to get from their figma files. So you get most of the way there for a much, much smaller fraction of effort.