I think the biggest difference for the All Blacks now is that they do not really have any leaders on the team. In the 90s, they had Mehrtens, Fitzpatrick, Brooke. In the 2000s, you had Umaga, Thorne, Howlett. Then the 2010s with Carter, McCaw, Read. Sure, they didn't win any world cups between 1987 and 2011 but those teams in the 90s and 2000s were more cohesive than what they have now.
Who do you have now? Beauden Barrett? Whitelock? Good players, no argument there, but these are not guys that will wake you up when the game is not going your way.
This just seems like a transition that is lasting a bit too long and carries over to a WC unfortunately for NZ. The future leaders of this team aren't there yet, and the veterans aren't the type of leaders that carry a team through these rough patches.
With 3 "easier" games coming up they have time to work on their set plays and gain some confidence before they face either Ireland or South Africa. That could be the key here for them.