For those learning touch typing, especially self taught, take the attitude that there is far more than just typing without looking, and using particular fingers to press particular keys.
The overall aim is to type: quickly, accurately, with minimal effort, and with good ergonomics.
As for what you type, for many tasks, it is useful to have your eyesight free to look at other things.
(It is similar with, say, the piano where if you want to read chords, lyrics, or sheet music while playing,
then you need to be able to play without looking at your hands.)
Having your eyesight free for other things is one of the reasons to touch type, consider reading
something out of a textbook, and how much harder it is to type what you see if you have to keep
looking back and forth between your hands, the source text and/or the screen.
Then, thinking old school, professional typists had to be able to type accurately. One single character
wrong, and they can probably get away with tipex and retyping it, but that takes a comparative age
compared to not making the mistake in the first place and going a little slower. (I write this as someone
who was self-taught, and wish I'd drilled accuracy into my technique way earlier.) Especially if
coding, not making typos is important. So learning not to make them is important. And as a suggestion,
consider how a pianist learns to press the right keys in the right order without making a mistake.
Treat accuracy in typing as just as important as accuracy when playing a musical instrument.
The trick is to go as slowly as you have to, to ensure correctness, and then only speed up when
you can do things correctly. If you go faster than that, you rush, you make errors, and then you learn
to make more errors, and to be tolerant of errors. Tolerance of errors is how errors creep in.
But going back to what I said: efficiency, accuracy, speed, effortlessness, and ergonomics.
Those are your real priorities, and they are often well-served by learning touch typing properly.
