The purpose of the "instrumental" attribute on the "performance of" Recording-Work relationship is to erase the lyrics language and lyricist from the data.  Many users are unaware of the guidelines, or worse intentionally violate them.

https://musicbrainz.org/relationship/a3005666-a872-32c3-ad06-98af558e99b0

https://musicbrainz.org/relationship/39a08d0e-26e4-44fb-ae19-906f5fe9435d

In the vast majority of cases, or even all cases, it is an error for a recording to use both the "karaoke version" Recording-Recording relationship and the "instrumental performance of" Recording-Work relationship.