People love to blame video games or the internet for anti-intellectualism, but I grew up on both, and I don't think I'm a particularly stupid person. I don't read either, never have, my sister on the other hand did read, a ton. And I think it's fair to say I'm a lot more intelligent than her (scored higher on SATs and ACTs, higher GPA, finished a harder college degree).
There are words in video games which you have to learn, they help expand vocabularies, and contain stories just as books do. Granted it's a much more passive experience because you don't have to use your imagination in the process, and I didn't only play games and hang out on the net. But I don't think that either of those factors are necessarily a negative thing; just as reading isn't a positive thing innately.
Reading fiction without challenging vocabulary might improve your speed at which you read, but unless you aim for something with words you don't know and you learn in the process, you're not gaining knowledge. Reading Wikipedia is probably one of the best things a person can do to expand their knowledge of the world around them, definitely better than reading fiction.