Route B alread blew me away a couple of times, but even during Route A I definitely appreciated how much the game made me think. More than any other Yoko Taro game.
It could be argued that it does so at the expense of the strong character drama of the first game, but I can't choose an approach, I think they're both masterpieces in their own ways, and I've always been of the opinion that the best kind of sequel is the one that leaves you completely satisfied, but still wanting to play the previous game. Instead of just surpassing it in every way, it's just different enough that you'll always have reasons to revisit the entire series.
Yoko Taro games have a certain feel that I can't get anywhere else, but other than that they provide very particular experiences, even if similar in some ways (which could be considered his artistic signature).
The best comparison I can think of is Fumito Ueda. His games always feel like Ueda games, but they're all very peculiar, rather than being iterative. Him defining The Last Guardian as a "greatest hits" of sorts got me really worried, but he was just being humble. It's an experience unlike any other.
Hidetaka Miyazaki absolutely nails the feeling of wanting to replay every one of his games no matter how many he makes, but we need to see what's up with his new IP, with no concerns of being similar to Souls, to see how different it can get from the formula, and which elements will still be the same, to create that Miyazaki feel.