You'd be surprised how many famous pop piano players didn't just have lessons, they had advanced training.

Elton John studied at the Royal Academy of Music. Alicia Keys is classically trained. Lady Gaga had lessons from the age of 4.

Even someone like Vangelis - nominally self-taught, and not a reader or writer - had lessons when he was starting out.

There are many many examples on both sides. That you can cite many who have had a lot of classical training doesn't disprove the point that many others have had minimal training.

Right, I'd argue that the people without training are going to be way more surprising.

First of all: they noodled by themselves, i.e. they gained their own intimacy with the instrument, which is something you cannot teach but only explore on your own. Secondly, you don't know if they didn't have any teachers or mentors or players they asked questions to or learned from. "self made" is not really a thing

I want to know which professional learned piano as a first instrument with just noodling. Maybe a handful of geniuses, but nothing more.

Most people get lessons so saying it is a handful is likely right. However I know a few who play for fun that never had lessons, and they sound good.

Honestly, no, you won't. It's very difficult and requires training. Those famous players made music their entire lifes work. Thinking that means you can just teach yourself at 35 with no musical training is idiotic.