Fun fact I type with 3.5 fingers at a reasonable speed and without looking at the keyboard. I never have problems with wrist pain. I tried to teach myself to use all 10 fingers and within a day or two was experiencing very noticeable pain! I switched back to my ad hoc method and haven’t looked back.

I've worked with people who barely knew how to type, which was annoying to see, but were extremely senior and productive.