It's plain that Illumination is banking on a distinct visual flair while sacrificing originality of story (and, in Sing's case, distinct vocal talent). There are worse films out there, but it all makes me happy that my youngest one is 10 and I will likely be skipping more of the automatic animation viewing destinations in the future.
If anything, this film shows us who the real star of the series is. There would have to be some major work done to incorporate Marlin as essential at this point. I am not sure Nemo ever mattered less.