SUMMARY

In essence would be nice to have the phone function as an additional audio sink for the computer. This would allow for example using headphones with the phone while being further away from the computer (so bluetooth headphones with extra steps). 
It could allow using the phone's speakers if those sound better (which can be the case for some) or even work for those who don't have speakers  attached to their computer (or they are broken) and just want to use their phone for this.