this is likely a byproduct of time issues. considering just how much story there is to develop, we had to settle for a lighter version of that deep thought.
Yeah, but IT is already 2 hours 15 minutes. They couldn't put an extra 5 minutes in there for something to separate the movie from the tagline to My Little Pony? Hell, even if it was something as a simple as "the belongings IT's victims had on them at the time they were taken can be used to burn/hurt/wound IT" which is why IT collects them (along with the bodies) in IT's lair. Like have them keep the pink shoe they found in the sewer. In the house Beverly stabs IT through the skull and IT just grins at her. Then Richie throws the shoe at IT and busts ITs nose, making IT bleed and retreat. Like that.