My wife always has the Subtitles on. Drives me crazy - I am a "just turn the volume up" kind of person. Yes accents c an be difficult, but you get used to them if you are paying attention. Plus when there are scenes or full shows that are darkly set, the words get really bright and cast a weird white haze on the rest of the screen.
A surprising survey found that younger adults are more likely to use TV subtitles than older generations. The YouGov poll found that, overall, 53% of Americans prefer to have the subtitles off when watching a show in a language they know, while 38% like to have the subtitles on. However, 63% of adults under the age of 30 prefer watching TV with the subtitles on – far more than other generations