Don't underestimate reading speed. Since it's a text-heavy game, it really shows in the playtime at the end. Some people just read really fast. Take visual novels for example. I can finish 30-40 hour VNs usually in 15-25 hours. Without skipping any text.
I don't think it's reading speed that is the factor, not bragging but I'm in the top percentile of speed readers and 45 hours is crazy fast.
BUT a big factor is that on my very first playthrough I let every voice play AND I let the text speed proceed at a reasonable conversational pace. I like to "hear" the voices being spoken and people speak s l o w l y by comparison to how quickly you can read text.