One problem here is that they show it off first with images, which basically makes it a very awkward and slow compositor. If you want to work with images there

One problem here is that they show it off first with images, which basically makes it a very awkward and slow compositor. If you want to work with images there is already Nuke, Houdini and Touch Designer. Using nodes to manipulate images hasn't been a problem for a few decades. They need to show more general cases, how to iterate, how to debug, how to manage state, how to manage errors, etc.