Well, the new blades are the main draw, but if you don't want to collect them all, then there's really not much of a point to new game+. You keep all of your blades with their unlocked perks and equipped weapons, so the game is easy even if you reset your character levels to 1.
The very few quests that have slightly different outcomes aren't worth it to see them either.
As expected, I enjoyed the game but not enough to commit to another 60+ hour playthrough especially when the game starts off pretty slow. I would've needed significant incentives to replay it, but ahwell. Thanks for the clarification as always!