I hear ya. I read (not just manga, but novels, non-fiction, poetry) more for entertainment than for learning. The reason that I prefer manga over anime is because of the pacing. When I'm reading manga, or books in general, I can read as fast or as slow as I want and can force myself to read at a pace that feels appropriate to what I'm reading. With anime, and movies and other types of TV shows as well, I'm forced to follow at the pace of what the director/writer feels is appropriate.
I feel like the statement above doesn't exclude manga (or any writing for that matter,) you are only allowed to go at the creator's pace. They control, ultimately, what you know just the same as a director. I guess in terms of time, you could probably read an "episode" faster than watching one. If you are watching a show, you are committing 20 minutes or so. Reading is more accessible.With anime, and movies and other types of TV shows as well, I'm forced to follow at the pace of what the director/writer feels is appropriate.