Hit up my friend after I watched this and broke it down this way. FLY loves Harry Potter, there's no doubt about that, so I'm always going to like these things despite Yates's previous films not doing a ton for me and not really caring about/actively disliking (that fat guy) a lot of the characters. The problem with this new series, and one that WB seems to be aware of with this kind of under performing, is that it's all plot. The best part of HP is the world, even the core series I like a ton, but it's the world that drew me in, and got me so invested in the series; here so much of that feels like an afterthought. Of course you aren't going to get the same sense of discovery that you would with the novels because so much has been established and, a lot of the time, perspective lets us learn with those characters, but we don't really get the vicarious thrills because all the characters that matter know the world already. So anything new is just 'oh, here's that, it works like this' and then it's gone.
Which is bound to happen in a film, I get that, less time for it to grow and, at this point, it's so constructed we know we're getting 5 more of these and roughly know exactly when they'll happen.
But the heart of it all is there's just too much plot here, and it's the whole point of everything. In the best HP books (Goblet of Fire, HBP, Chamber to a lesser extent) you get a self contained story that is compelling on its own and based in that world, which eventually connects to the larger conflict. The series struggles for me when there's a disconnect between those two (OotP is awful, and Deathly Hallows gets so far from Hogwarts/needs to be so main plotty that it's unavoidably rough at times), and with Fantastic Beasts it's pretty much all disconnect because, despite only being in the second film, shit is popping the CINECAST! off. Like I know what 'the crimes of Grindlewald' are, but not really because he doesn't do all that much here, so it's just a subtitle that doesn't really tie in to the individual story because that individual story doesn't mean anything. It's just a part of a whole. Aside from already knowing the conclusion, which I don't think is necessarily bad because that can still be compelling if you're invested in the world, the stage is set for that central conflict to come bubbling. There's just no room to breathe. And that kind of sucks.
But it could maybe still come together, and perhaps the whole is greater than the sum of its parts. It's hard to say this early, though that on its own has to be concerning when you figure there's well over 10 more hours of this during the next 11 years. I only watched the first Hobbit, but I wonder if it's a similar problem WB had there.