It seems to me that the popularity of Jojo Rabbit with so many festival audiences is surely due to the total dynamism of little Roman Griffin Davis, who plays little Jojo.
Jojo Rabbit is funny for a while, but then, you know, the Americans bomb Berlin and kill a lot of people, and long before that there are Nazis doing evil things, like, you know, carrying out a genocide. And, as it turns out, Jojo Rabbit is mostly just not funny.
Or... that would be true if it were directed differently. Instead what we have with Jojo Rabbit is a very good script that was poorly directed. Waititi understood on paper what the film needed to be, but he wasn't really able to execute that. And I say that as someone who really liked Hunt for the Wilderpeople. I think Waititi can do comedy very well. He hasn't figured out how to balance that out with anything else yet.
Sam Rockwell is good. Scarlett Johansson is very good. Roman Griffin Davis is absolutely great.