This is super interesting - I have typed "wrong" since the time I first picked up a keyboard, 6 or 7 years old, back in an age where typing was not taught in school or an expected skill everyone was just automatically meant to know. As such, I developed my own "style" which looks a lot like "pecking" a lot of beginners will do, but has adapted over the decades to something that is my own.
I typically just use the index/middle finger on my left hand that covers most of the left hand side of the keyboard, depending on word (index might reach for the 'y' key sometimes) and the pinky for shift key. Right hand uses mostly the index, ring (for hitting backspace and enter) and thumb (for spacebar). I've often wondered if I was ever able to retrain myself to do it "properly" whether I'd type even faster than I do. now I am not sure.
I have "peaked" at 125+ wpm in 1 minute tests, and in casual conversation with familiar words, probably can maintain easily around 110-120. I think for most things I typically cruise around 100 without trying too much. It is a nice skill but I've never been able to figure out why I type so much faster than most people I meet, especially given being self-taught and the unorthodox way in which I type. Often when I am showing something on a terminal, for instance, which includes a lot of auto complete and muscle memory, I need to slow down by about 10-20x for people to follow what I am doing.