I actually liked this 3rd installment more than the previous two. It's not without its faults but I still liked it.
A casting choice that did puzzle me was Anton - the wizard who was running the election. He looked SO much like Mads (playing Grindelwald) that it was almost confusing for a few minutes. Same facial structure/cheek bones/etc. They look eerily like real life brothers.
That being said, casting to replace Johnny Depp was going to be hard no matter who they chose. Johnny was a great Grindelwald. Mads did a good job. I'm not sure how Johnny & Jude Law would have done in the opening scene. I'm not sure how that dynamic & chemistry would have been with the way Johnny played Grindelwald. Mads did okay. I'll always be curious as to what that would have been like - seeing them in that scene.
The title is also misleading lol. Secrets of Dumbledore just doesn't fit this movie or script. This is more about the Election and Grindelwald than Dumbledore, in my opinion.
It's a solid movie. I don't get the harsh reviews.