Indeed, interference is the greatest enemy of analog signals. It's not impossible to shield, though. Other parts are already shielded, but I can see how it could have become more challenging.

Btw, I thought it was more related to frequency than components size, but now I'm confused, I will look more into it when I have more time. Thanks for bringing this into the topic.

Not to mention it’s a form factor that requires a considerable amount of space. That for the majority of users is doing nothing but taking up that space for no reason. Every phone without a headphone jack is capable of getting a jack with a simple dongle. What I love are the people who have absolute no problem with a dangly cord around their neck but lose their shit if you have to connect a 1 inch piece of wire first. They act like it’s a bag phone you attach to your side. And as far as audio fidelity goes the DAC inside a cell phone is nearly always garbage and you’ll need your own DAC anyway which is easy to obtain when it can be powered by your phone.

I'm not an expert either, but the DAC on my Galaxy S10 sounds amazing. It's just a question of whether manufacturers bother implementing it properly.