Dialogue from movies and TV shows has become more difficult to hear in recent years, prompting many to switch on subtitles for much of what they watch. As this video from Vox details, the reasons for this shift come down to a desire for realism, choices that filmmakers have access to because of technology, and mediocre at-home sound systems on TVs, computers, and devices.
The drive to watching things at home is causing previously-acceptable audio to be less desirable.