FWIW my son went through the same sort of thing during emerging literacy and it drove me kind of crazy. He started with simple texts, then started coming home with “graphic novels”. I just let him do it. He was stuck on those for a bit, started getting interested in World Record books (which, again, lots of pictures and not much writing), and then…read a Roald Dahl book a day for two weeks. For whatever reason, the switch flipped.
Throughout it I continued reading to him daily, mostly stuff that he comprehends just find but find too difficult to read on his own.
I think it just comes in its own time if nurtured.
Edit: I really like what John Gotto (I think…he wrote a book called Dumbing Us Down) observed about literacy; for a long time it just developed naturally without much formal instruction. I had that in mind for our kid and am glad I did.