Strings are already a Collection, there is not firm need cast them to a list to live inside a Vector. I like the idea of maintaining the original type if someone wants it back later (possibly after transformations of the values).
Why is it pointless for a vector, but not for a list?
I guess it really isn't. I was thinking of just .upper() and .lower() where upper/lower-casing each individual letter is the same as doing so to the whole string. But for .replace() or .count() or .title() or .swapcase() the meaning is very different if it is letter-at-a-time.
I guess a string gets unstringified pretty quickly no matter what though. E.g. this seems like right behavior once we transform something: