Still feels like history written by the victors (of WW2 and computing, eventually) in this case. If you want to be mathematically precise, it's been proven to be Turing-complete. If you want to use common sense (IMO better), it was one of the most significant leaps in automated computation and simply didn't need to do more for its intended applications. For conditional branches to make sense, you also need a fast temporary storage array (since it would be awfully slow running directly off tape like a Turing machine), and to realize that all that effort makes sense, you first need to play with a computer for a while and discover the new possibilities.