It’s not you (or your hearing aids) — movies ARE becoming more difficult to hear
Actors in Old Hollywood television and movies used an exaggerated and over-the-top style when they delivered their lines. Lately, actors tend to deliver their lines in a soft and breathy voice, especially if it’s a drama. It’s an artistic choice — and just like any other trend, it changes over time.
Sound isn’t a priority
Televisions keep getting bigger. Therefore, a lot of time and money is invested in making sure what you’re watching is visually pleasing. Sound and microphone operators report that their work has become less of a priority on set because of this. Additionally, filmmakers sometimes spend years on a film, and they become incredibly familiar with the script. They don’t have the perspective of someone who is listening to the movie for the first time.
When it comes down to it, Hollywood is a business. They are paid by artists to have their music highlighted in a TV show or movie. Unfortunately, any background noise like music will also make it more difficult to focus on speech.
The way that sound is mixed for movie theaters, TV, and streaming services is different. One way of mixing sound doesn’t translate well to another. A movie theater has a dozen or more speakers for a full sound scene. When that same movie is played on TV, it’s only coming out one or two speakers.
Reference: Ben Pearson SlashFilms