With no pawns, you mean? Of course it is. But people blunder, so it's still worth trying to play.
Queen vs. rook and bishop endgame
Well, because there's no way to force a win, I guess. Position matters, of course, if the pieces are uncoordinated, they can be cut off and eliminated. But in general, if you just hang around in the center of the board with all three pieces, the queen won't be able to force you to the edge where you could be mated.
Mind you, I haven't studied the subject, but still, this is what makes sense to me.
Is a simple Queen vs. Rook and Bishop endgame a forced draw? sorry if this has been asked before, but I couldnt find anything online.