This did compile and the audio output from the echo is played on the media_player, but the audio is also played on the Echo itself. Previously, changing the i2s_dout_pin from GPIO22 to GPIO21 prevented the Echo from playing the audio (I think by directing audio data to pin 21, which is not used).
I'm not sure what you meant here:
Media player is also a speaker using an arduino library (not compatible with esp_adf as that uses the esp-idf framework and not arduino). If you want to use the media player, you have to get rid of vad_threshold and the esp_adf.
I tried removing "vad_threshold: 3" and the "esp_adf" component: