I still get a kick out of this...
2013 - "omg the headphone out on DS4 is god awful. Why would you do that to your ears?"
2017 - "what? No headphone out on joycons??"
Headphone out of the controller usually has awful audio. Still, I do wish Switch had A2DP or such enabled. In the meantime pick up a cheap/reliable BT audio dongle and plug it in the top of your Switch.
Xbox One controller does a great job of stereo output from controller.
OT - The lack of headphone port did surprise me, perhaps they can revise this for future models. To be honest I only use the headphones in handheld mode in bed.