Doom Eternal. It has a lot of lore and text logs to read, and he's gonna grow some hair on his chest while slaying demons!
For real though, I'm not sure if he's gonna learn how to read by playing video games all day. Certainly not from the ones that are appropriate for younger kids. He could probably get a lot out of computer RPGs like Pillars of Eternity or graphic adventure games like Monkey Island, because those games tend to be plot-heavy with lots of text. However, I'm not sure how riveting those kinds of games would be for a younger kid in terms of gameplay.
Honestly, if I had that kind of a problem with my kid then I would just get him into reading. It could be literally anything as long as it has text to read in it. Comic books, gaming magazines, or some kind of educational encyclopedias with pictures in them. It can be a great tool if you just want your kid to learn reading properly.