Don't use `auto`, full marks, but the gitattributes file is indispensable as a safety net when explicit entries are used in it.
I mean, the whole point of the file is not everyone who is working on the project has their editors set to lf. Furthermore, not every tool is okay with line endings that are not CRLF.
When used properly (sure, ideally without auto), the git attributes file as a lifesaver.