I'm just speaking in terms of my personal opinion. Most of the really good headphones are wired (i.e., higher-end audiophile headphones like Grado) and will pro

I'm just speaking in terms of my personal opinion. Most of the really good headphones are wired (i.e., higher-end audiophile headphones like Grado) and will probably remain so. People also like to supply their own amps. There are some portable Bluetooth headphone amps, but they're not so good compared to USB or analogue amps.