I can see this being useful for parsing. You often want to report all of the parsing errors to the user in one go, so collecting them into a list or iterator is useful.

But yeah, still relatively obscure.

And I’m guessing, “evert” is simply the respective English word: https://en.wiktionary.org/wiki/evert
As a non-native speaker, I didn’t know that word either…

Its for this pattern which useful, but not intuitive:

let res = my_collection
.iter()
.map(|x| method_that_returns_result(x))
.collect::<Result<Vec<T>, Error>>()?;

So it turns a Vec<Result, Error> into Result<Vec<T>, Error>, and you can turn it into Vec<T> simply with ?. Otherwise you would probably need a for loop.