The characters are vile. Two of the girls especially are spoilt, uncontrolled brats who are horrible to watch. The parents should be ashamed of their parenting skills, and the awkward situation they put their children in. The CGI is really poor by today's expectations. A puppet would have been far more convincing than Caine's uncharismatic Psammead. It's a really poorly made movie which does the original story no justice.
And yet, my children love it (aged between 3-6). They've got the choice of masses of movies from various streaming services and they keep coming back to this. All of the greatest family friendly movies from the last thirty years, and they choose Four Kids and It. I'm not sure whether this is because my children have dreadful taste in films or whether it is genuinely engaging for a younger crowd. Either way, it clearly appeals to its target audience.