I had just upgraded to iPadOS 15 and the caps-lock-as-control setting reverted to the default. I went into settings and changed it back, but I did so with caps lock accidentially enabled.
This left the folio keyboard stuck in caps lock. I had to go back into settings, set caps lock back to caps lock, press the caps lock key to disable, then I could make it a control key. But trickily, the setting change didn't seem to take effect until I swiped out of the screen where you change that setting.
ANYWAY, I'M JUST GLAD I FIGURED IT OUT.
BTW, why does caps lock even still exist?
Dunno, but in my country we use a QWERTZ layout where you can't write the letters Ě, Š, Č, Ř, Ž, Ý Á, Í, É without caps lock, because with Shift those keys produce 2, 3, 4, ..., 0
So that's why I need it. :)
It was useful on some old machines that tended to prefer uppercase input. On typewriters, the shift lock key (which is slightly different) tended to be used when people wanted to add emphasis to a word or phrase.
As for modern computers, it is less useful. When one of the keyswitches on my keyboard failed, I replaced it with the keyswitch from the capslock since I figured it was the one key I was guaranteed to never use.
Auto doesn't make total sense to me, but it seems originally the Romans had only the letters we know as capitals, and none of the extra characters like semicolon.
IIRC sometime in the middle ages lower case letters were added, but it's not clear to me why and how it ended up getting a bunch of different rules (eg German capitalises nouns but in English it's only proper nouns).
https://www.termsfeed.com/blog/all-caps-legal-agreements/
There are also theories out there about why our names appear in all-caps on government documents, relating to the concept of treating an individual as a 'corporation'.
Never had the problem when using SharpKeys to rewrite the registry.
When I first started doing caps-lock-to-control, I mapped my physical control key to caps lock. Eventually, I stopped bothering and kept it as control.