Shouldn't it be possible to compile Lottie-animations down to SVG+JS? Is that maybe just something that's still missing?
That’s exactly what the library does for its web renderer. There’s a svg renderer and a web renderer.
The library does this in during runtime, though, if I’m not mistaken? The original commenter is probably referring to a build step that extracts the Lottie content and only leaves JS and SVG in the final output (which is not the case, as the Lottie web player library itself needs to be included as well, to render the animations and provide interactivity APIs during the rendering of the web page).