I never expected Joker 2 to make anything even remotely close to the first one and I've argued about it here a few times. The first one was a lightning in a bottle, it took everyone by surprise, it was fresh for the genre and one of those things where it's very difficult to replicate its success. The second never had a chance to make a billion, especially ever since they announced it would be a musical. It was also kind of obvious that it would be a forced cash grab from the beginning and with a director like Todd Phillips that was bound to somehow reflect in its overall quality.
However, I was expecting something close to 500 million, not a disaster of this magnitude.