A useful counterexample, where one wants to see all errors, is validating form input. But it's very much ok to say your library is not meant for that use case!
We currently expose error as a tree structure so that it's easy to map an error to a value or build custom error messages (we only provide debug error message) and I haven't been able to come up with a satisfactory error API that accommodates multiple error paths, but you raise an excellent point. Thanks for pointing out.