I know this sounds silly, but reading genuinely never captivates me. I am able to imagine things with my minds eye, but it requires that I just completely focus on picturing something and ignore the book while I do it. I think I just have a bad imagination or just a stupidly short attention span for anything that isn’t a creative endeavor.
When I read informational content (research papers, history, geography, etc) I can straight up read for hours because I end up learning something cool.
My wife can read books for hours, but I struggle to stay engaged. Fiction/fantasy especially is rough even if the topic is inherently interesting to me. Poetry and short stories are okay.
I think reading requires a lot of curiosity and empathy. Sounds like you already have the curiosity bit down. Just need to translate that curiosity into empathy towards the characters you read - what happens to them, how they resolve the story’s conflict, if you feel they are better people in the end. When you think about it, a lot of fiction is just critical/sociological / philosophical theory expressed aesthetically through story elements.