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.
Have you tried audiobooks? I recommend ones that are acted out with a whole cast (a lot of the Sherlock Holmes books, Dune, Daisy Jones and the Six). I feel like it’s a great way to dip your toe in because you have the wonderful voice acting and then can focus on imagining the scenes and characters. By the time you’re immersed in the story, hopefully it’ll come more naturally!