Right, but the branching factor increases exponentially with the scope of the work.
I think it's obvious that they've cracked the formula for solving well-defined, small-in-scope problems at a superhuman level. That's an amazing thing.
To me, it's less obvious that this implies that they will in short order with just more training data be able to solve ambiguous, large-in-scope problems at even just a skilled human level.
There are far more paths to consider, much more context to use, and in an RL setting, the rewards are much more ambiguously defined.