I'm not sure we're in disagreement: I agree that a rock's experience is practically null (maybe the fact that its atoms are connected and may be pushed and pulled together makes up the tiniest grain of internal experience), and that a worm's experience is still a world apart from ours and probably much closer to a rock than us. If we were to score an experience on how human-like it is, I'd expect the various elements I named to each refer to exponential or greater increases in score. Comparing the depth of a worm's experience to a human's would be like comparing the volume of a nearly 1-dimensional line segment to the volume of a many-dimensional hyperobject.

Our brains are just tons of biochemical circuits working very mechanistically, with many interesting feedback loops going on that make up our internal experience. A worm's brain has a small and probably countable number of feedback loops going on that I assume make up its tiny internal experience.