All the acting in IT Chapter Two was right on except for the one person I thought would not disappoint - Jessica Chastain. She's not terrible. She just doesn't deliver any sort of energy or charisma to her role the way Sophia Lillis does. Chastain doesn't seem very invested in her character. Let's put it that way.
The message of IT Chapter Two seems to be that we all have to face our fears and our pasts to truly move forward and live a healthy and productive life. Social commentary is served on the subjects of bullying and shaming someone's weight and sexual orientation, which I'm sure will cause some controversy among some circles.