What’s the point of descriptive audio commentary tracks?

[MenacingMonk]

Watching Sicario 2 and switched the audio. Had me when I heard it. I know there is descriptive subs as well.

So why is it needed?

 

[Deltron]

maybe it's for blind people

 

[prophecypro]

For the blind or visually impaired just like close caption subtitles for the deaf