trade-offs for everything.
there was a time when stereo was seen as unnecessary faff, too.
edit: movies are mixed for theatres and no longer are the home releases adjusted to suit.
I think if you want to make widely accessible audio content, you should be taking this into account. Make it intelligible in mono first, then worry about the rest.
https://lifehacker.com/how-to-fix-movies-that-are-really-qui...
https://ffmpeg.org/ffmpeg-filters.html#acompressor
https://ffmpeg.org/ffmpeg-filters.html#dynaudnorm
To use them with mpv you'd do something like `mpv --af=lavfi="[dynaudnorm=param1=value1:param2=value2:param3=value3]" ...`
(make sure the first parameter is preceded by a '=', not a ':' because reasons)
If that's commonly the case then whatever is doing the downmix isn't fit for purpose.
I found on Kodi you can boost the centre channel when downmixing, this helped quite a bit for me but I still watch with subtitles.
even worse is if you don't downmix to stereo, and all you are hearing is front left and right, which is often just the reverb effect channels for dialogue