I think I just watched a several hour setup for a much better film...
There are elements to the modern Witches that work pretty well. A decent amount of the humour lands and casting choices are great; Anne Hathaway throwing a tantrum is a lot of fun and the world simply doesn't deserve Octavia Spencer, she's brilliant throughout. CGI is a mixed bag, with the magic, witches, and mice all looking pretty good, but then the cats and rats are awful. Whoever animated the mouse run cycle, though, bravo: nailed it!
I'm not hugely knowledgeable about the original story, either, but I thought the setting, characters, and underlying lessons on class and race were all pretty solid. I'm fairly sure the original book doesn't centre on a Black family, but it's an excellent fit, so I thought the modernisation elements must have worked quite well. Beyond that, though, the story is a bit thin, even for a kids film. The witches themselves are quite two-dimensional, there's little in the way of logic as to why events unfold how they do, and his mouse being another bewitched child just felt a bit lazy. I also didn't care very much for either of the other two kids, and the ending was, well, really weird.
The biggest shame is that the ending pretty much guarantees that the better story – the one where we get to see Octavia Spencer and three mice travel the world assassinating witches in a Van Helsing meets Stuart Little mashup I'm surprisingly invested in – simply won't happen. No, instead they're going to arm the children of the world, years later, when the main characters are all dying. The hell is the point and/or moral to this story? Life sucks because you have responsibilities? Bad things happen, get over it? Disability and otherness are sort of fine, but expect large parts of the world to be horrified of you and that's okay? Little old woman are all evil? (That last one doesn't even work in-universe, where the setup is that witches are all old ladies, and then none of the witches look older than 40)
Who knows 🤷♂️ Combine with some lacklustre pacing and a whole heap of "why is no one else reacting to everything that's going on here?" and Witches becomes a slightly dull, very forgettable film. It's not bad, per se, it just isn't good.