I was thinking how in The Fellowship of the Ring (the book), Tolkien never really mentions child hobbits but otherwise paints a picture into which it’s easy to insert them. The Shire is a bustling town! But in the movie, Jackson absolutely adds hobbit kids because their absence would be weird now that we have to see them.
But I also get that, like, it’s not really weird that kids have no place in a Jason Bourne movie. It’s all grownups, and it’s ostensibly set in our world.
(I still find it weird and jarring as an adult and a parent to watch Star Wars and notice the total lack of actual kids, and not just crypto-kid-coded presences like the jawas, an alien in the cantina, and Luke himself.)