Yeah this perplexes me too because my hearing is otherwise decent but I almost always need subtitles. I've looked into it a bit and some people are surmising th

Yeah this perplexes me too because my hearing is otherwise decent but I almost always need subtitles. I've looked into it a bit and some people are surmising that it has to do with poor audio engineering for home release. Films audio is recorded to be played back in a spacious theater with surround sound, good acoustics, and speakers with high range. Then you have people's home audio setups: noisy listening environments with people right next to the audio source, poor acoustics and stereo sound, and poor speakers from laptops, smartphones, or those built in to flatscreen tv's. The sound mixing also relies on these factors as well as the theater experience so explosions are super loud and quiet moments are eerily silent. (Not to mention that dialogue takes a backseat in many modern films) The audio might be poorly remixed, if at all for home release and the poor playback equipment exacerbates the issue. It's similar to developers saying "works on my machine", where in this case the machine is properly calibrated, thousands of dollars, and top-of-the-line.