if origin is Union or origin is UnionType:
        return any(field_annotation_is_complex(arg) for arg in get_args(annotation))

    return (
        _annotation_is_complex(annotation)
        or _annotation_is_complex(origin)
        or hasattr(origin, "__pydantic_core_schema__")
        or hasattr(origin, "__get_pydantic_core_schema__")
    )