You are right, dribbling is much harder than backflip because you need not only balancing control for the lower body but also arm and hands control to interact with a physically simulated object - the ball.

yeah. there are other videos that are actually more related, such as Atlas running whilst being pushed by someone with a stick. Clearly it's capable to adjust movement to unexpected external events, which seems like a stepping-stone towards dribbling (probably wont be able to predict perfectly how the ball will bounce). Still, based only on public videos, they have a long way to go.

I haven't seen a video from them in a while though, so who knows, maybe Atlas is already working his ballgame in secret somewhere.