Nobody makes finished recordings for distribution with a cell phone. Field recordings for use as samples? Sure. Something to get the overall feel of a performance? Sure. A dedicated mic on an instrument because nothing else was available? Sure.

But recording when it matters is dependent on the microphone, the pre-amp and the A/D converter, none of which are of suitable quality in a cell phone to be the basis for a "serious" recording.

This is not what I see on YouTube. Professional recordings are outnumbered by amateur ones. They are as "finished" as they're going to be and sometimes they get a big audience.

Sure, maybe most professionals don't do that but you said nobody does that, as if amateurs don't exist.

Well, I guess there's also recordings with a line-in from a mixing console with the mics&pre-amps on the other side of that, and sure, that's a thing, and I ignored that with my comments. That setup gives you just-about-good-enough quality (certainly way better than ye olde "direct from desk" bootlegs of past time).

I was thinking more of setups where you connect a mic/pre directly into the phone.

Most of the time I've seen people doing this, however, they are using "native" recording apps on their phones, not a browser.