What’s the benefit of ASL versions of TV shows/movies?

I was noticing there are several shows and movies that have been having ASL versions. My first thought was “That’s great, it means more people can enjoy these shows” followed shortly by “Wait, aren’t subtitles a thing?”

I checked out the show thinking perhaps they had the actors signing their lines (how cool would that be for an adaptation, right?) but it was just a picture-in-picture of an interpreter, similar to what you’d see if a public speaker had an interpreter.

So, here’s my question: what’s the added value in having an on-screen ASL interpreter as opposed to subtitles? I can certainly understand for concerts and music (and frankly I love watching videos of concerts with ASL interpreters. They really capture so much of the character of the music), but isn’t the body language of the actors already accomplishing that when just using subtitles?

Apologies if I’ve been inadvertantly insensitive, this is a question coming from a place of genuine curiosity.