My problem isn't the actual reading of words or the investment of time. There are stimulants that work wonders for me and allow me to do it.
It's the parsing of all the unnecessary information to get to the point of the material. Part of that might be because I'm on the spectrum and struggle with understanding context, though.
Fun anecdote: 30% of people with ADHD/ADD are somewhere on the spectrum; 70% of those on the spectrum are ADHD/ADD.