Long before audio books were a public thing I received a special tape player for listening to audio recordings of my school textbooks because I have low vision. I was ecstatic to learn that I could adjust the speed and could still understand the book at something around 2-2.5x speed. I don’t know to what extent other bling or impaired persons use the speed controls but I’m guessing it’s designed because some people can process the information and others more slowly and this isn’t a bad thing per se. I also agree that the information glut is not a good habit but listening to something at a faster speed is not in abs of itself information glut. Sometimes the bottleneck in presentation speed is the speaker not the listener.