When everyone has accepted long-standing thinking, that's the time to re-assess the other direction.
I think that's the case here with the enforcement of Publisher copyrights in YouTube regarding cover music videos. I think that musicians are too quick to be intimidated by aggressive attorneys working for the Publishers.
Copyright misuse is a defense for infringement. So, yes, you may be infringing, but you may have a defense against the Publisher's claim of infringing.
The Publishers aren't just flagging videos, they are claiming the entire video, including the embedded sound recording and visuals, thereby claiming content beyond the grant contained in the copyright for the composition. And, then subsequently monetizing content that they have no rights to. This could be found to be impermissible, and they could be barred from making any claim of infringement on any song in their catalog against any YouTube musician.
I think what should probably be done is to set aside all cover videos, so no one can monetize, until the parties have reach some equitable agreement on the distribution of revenues, include the owners of the derivative works, namely the sound recording and the visuals.
But, this isn't what being done. So, why is this permissible? It may not be.