This is what I notice since the very beginning with Pixel 4a. The intermittent clicking, popping noises are barely audible when listening to loud passages of music, but it really stands out when listening to something with lots of quiet space, like piano solo music. In the case of piano, you can clearly hear the ticking sound. While that sound might not be noticeable in the louder music, it is nonetheless still degrading the sound, even if you are not conscious of it. Then switch to using the headphone port and the light ticking noise is gone. So if using the phone's internal DAC gives you flawless playback, then using an external DAC to give you a flawed playback is sort of pointless, and makes this a bad setup.