mpris-proxy registers every MPRIS player with BlueZ, which then sends AVRCP commands to one of them (mpd). With it disabled, BlueZ sends the buttons as media keys, which xmonad passes to playerctl.
mpris-proxy registers every MPRIS player with BlueZ, which then sends AVRCP commands to one of them (mpd). With it disabled, BlueZ sends the buttons as media keys, which xmonad passes to playerctl.