caps lock but that toggles itself off after a single character. it's made for people who have dexterity issues and cannot hold multiple keys at the same time.

It only lasts for one character, it works on all characters (for instance Caps Lock won't change a "2" India an "@"), and it also works for other modifier keys like "Ctrl" and "Alt."

It's an accessibility feature. If you only have 1 hand, for instance, some shortcuts would be impossible without it.

Not exactly. Using capslock is more cumbersome because you have to press it, then type your letter, then press it again. It doesn't sound like much, but imagine if the caps button on your phone worked like that. Press it once and you TYPE LIKE THIS UNTIL YOU PRESS IT again