Sadly a lot of modern children's books are pretty dire and uninteresting to children. My DS was the same, he could read, but just didn't want to as he was bored with it all.
We just did our best to find things he would read, such as comics, event programmes, newspaper articles, etc. We got him things like Top Gear, Club Penguin, Football, World record annuals, etc.
He's now 14 and still won't read fiction unless he has to (i.e. if it's school homework). He just isn't interested in "stories". We had a good chat with him about it a few months ago, and he says he wants to read about real things, i.e. facts and figures, etc. We got him Alan Sugar's biography and he lapped it up, read it in a few days, so we're getting him others, so at least he's reading something.
I never read as a child, though I read a lot now. My OH used to spend all pocket money on books, and preferred to read rather than playing out, but I've found out it was more a matter of relieving boredom, i.e. nothing better to do, rather than a real love of books. To be honest, I think that's why I read now. These days, kids have so much else to do, with consoles, Ipads, social media, etc., so you really need to latch on to something that really catches their interest rather than just make them read for the sake of it.