It aims to be everything (from vector to raster to animation to publishing to compositing and so on), not sure how that ambition will turn out but they seem to have a very good team and are making good progress. It's node-based, but you can edit stuff using only the familiar layer stack if that's your thing. Check out the recent livestreams to see how the procedural workflow looks like : https://www.youtube.com/watch?v=6iLiaSGSnPs and their interview on Developer Voices : https://www.youtube.com/watch?v=ZUbcwUC5lxA
There's no raster editing yet, and no painting, cf roadmap https://graphite.art/features/