I think the split focus did hurt SB a lot. While I was disappointed the Ul'dah conspiracy was retconned out of relevance (the only thing that changed was Raubahn losing an arm, but that didn't change much, and he'd get a magitek replacement eventually), the rest of it was decent. You got to travel but the focus was cohesive.
Meanwhile in SB not only do both narratives suffer from some detours, what bothers me the most is that the quality differs between them. Had the Gyr Abania arc satisfied me as much as the Doma arc, I'd have less to complain about, but it doesn't. Story and characters both it falls short, imo, and when that's half your expansion, that matters.
