Does any system (modern or not) actually use `\r` for anything? Because I'm not aware of it being used alone. I'm not even sure why software today still differentiates between the two instead of treating any of `\r`, `\n`, `\r\n` as a single line break. I can maybe see it being useful eg in word processor to differentiate manual line break from paragraph break, but that's not a plain text format; in the vast majority of cases, treating them as the same character in parsers shouldn't* cause any issues.

* shouldn't ≠ doesn't