Another perspective.
Once upon a time, it was pretty normal to watch something and not be able to pause or rewind. It was perfectly expected that you might not get every single word and you didn't really think twice about it, just like you don't think about how you miss some words in real life.
But now, we can pause, we can rewind. We can get exactly what was said and we get preoccupied with making sure we understand every single word. So captioning becomes even more critical.