they mix audio for cinemas with 5.1 or 7.1 speaker systems. And then they take that version and smoosh it into stereo :) which then comes out sounding absolutely terrible because the mix was simply not made for stereo
I think the issue is with volume levelling; your statement implies the issue is channel separation. Listening in surround sound won't mitigate the issue, unless you intentionally boost the center speaker
Someone sharing a solution for one platform doesn't obligate them to support every platform.
That said, this kind of functionality is sometimes called "noise compression" or "volume normalization". Guitar compressor pedals do this. So look for those in your TV audio settings or audio system settings, but I wouldn't hold my breath that it will be there on most TV models.
Also, sometimes it can be due to the way the sound is mixed to however many audio channels the media uses and then how your setup remixes them for how many audio channels you have available. Check your settings to see if the speaker setup matches what you have. Also make sure they are all properly plugged in and actually driving audio through them.