The sounds in the arcade give it a good atmosphere, but it can be a bit much to listen to for extended periods of time. While I was grinding for the Wowozela, I had the “Effects Volume” turned all the way down because listening to the arcade ambiance for hours would’ve driven me insane. I think being able to have the audio for the game you’re currently playing be separate would be nice because it would let you better take in the noises of the machine you’re playing.
For example, I didn’t know Avalanche had music until after playing over 5000 games of it.
Another example is with Stack ‘Em, where the sounds of the blocks hitting the walls are better lined up with their position than where they’re visually shown to be. And getting to stage five take a tad bit of focus, which is hard when you got the Wheel of Fire goin’ on about cheese, Meteoroid Mania groovin’, and Skee Ball goin’ “woo woo woo”.