I dunno, we have a decent Dolby Atmos system I've assembled over the years which sounds immense & has a setting to accentuate speech, yet I always use subs for TV & movies. My brain is hopeless putting names to faces, the subs help me with this (plus slang & accents).
I think it's something to do with how my brain processes sound as I have the same issue with songs - my brain doesnt comprehend lyrics, I don't know the words to songs I've heard thousands of times no matter how well known the song is, maybe a few lines from a chorus but that's about it