It increases your flexibility to read quickly when needed and appropriate to the material and your goals.
Most people are often under time constraints.
It can be more enjoyable . In other words, speed reading a tax booklet would not increase comprehension, but speed reading a novel, magazine, or newspaper would. Subvocalizing means you are reading around 200-250 words per minute. Your brain is comprehending individual words, which it then has to synthesize into whole thoughts. Speed reading means you are reading faster than you can say the words in your head, comprehending whole phrases and ideas rather than individual words.