Passing an analog signal fractions of a millimeter from a bunch of digital signals is a recipe for very crappy sound. I have yet to find an analog USB-C audio adapter that didn’t have terrible quality and usually some hissing or other noise too.

I have some balanced armature earbuds, and they are sensitive enough to pick up noise from poor digital grounding even in the 3.5mm jacks in a lot of phones. Additionally, they are often too loud even on the lowest digital volume setting. 8 years ago I actually made an inline attenuator, which solved the problem on my phone at the time.

My current phone is a pixel 6. I got a USB-C adapter with a DAC built into it, and it actually sounds pretty good. The volume levels are reasonable, and there's no noticable noise other than perhaps an unnoticeable hiss.

Years ago, I had a desktop case front IO panel with a really bad ground loop. I ended up cutting the molded over plastic open and cutting the PCB traces between the audio ports and the USB ports, and the problem went away.