I’m also not in that age group (I’m late 30s) but I’ve been watching TV and movies with closed captioning enabled since I was a kid and have found that it helps my comprehension of what’s going on with plot lines, etc, immensely. Maybe I’m just a stronger reader than listener, but I’m at the point where I vastly prefer to watch movies at home rather than at a theater because I can have CC on by default.

I’ve also always had CC on for my kid and they’re an excellent reader. I don’t have any concrete evidence for it but part of me thinks their strong reading skills are partly due to that.