I dont think body odor ever played an evolutionary role. As far as I know body odor is caused by bacterias eating and multiplying whenever we sweat. If this is the case body odor is here because we sweat which isnt that common within the animal kingdom.
(Although dont quote me on any of this, this is just what I seem to remember and Im lazy to look it up - tldr i might be lying)
This isn’t really a cable issue though. The inaudible dialogue is due to bad masterinf of the sounds for home systems (i.e.: the slunds were originally mastered for 5.1, 7.1,or for fucking cinemas with 128 channels)
Or it is just the choice of the director, because he likes it that way (Cough Christopher Nolan Cough)