Machine's problem imo is the kill time. RB threatens a one shot on people who sprint at it while machine folds to that so it's forced to play methodically and clear things thoroughly. It has the tools to do that though so that makes it really good into ratty comps but aside from that it's rough

Pre nerf RB especially was such a powerhouse that if your comp enabled it and the person playing it was good then it was such a problem you could force upon basically any comp you were fighting. Without that level of power you can't really run other midline AoEs the same way as that