It doesn’t work this way.
Publishing is only one of the music rights. There are Mechanical Rights, Production Rights, Artist’s Rights. among others.
Other sources of income:
CDs, MP3 albums, Vynil, licences to potential external playback such as trailers and commercials, radio play, theatrical releases,ring tones, printed scores, usage of clips on YouTube, TikTok etc. Including usage of music as played by others on a piano, or other instruments, etc, etc, etc,…
Call me crazy, but it seems you want this to happen. I am trying my best to explain why the film-music industry is in a good place, and at no point, anything I mention is satisfactory, as the way you paint this, change is coming and there is nothing we can do about this.
Whatever I state is irrelevant, and in a few years (according to you) we, composers working in low to mid-tier films, will be out of work.
Not that I personally care to be frank. As I said, if it happens, it will be a sad day, but I will happily do something else.
I had a fulfilled career up to this point and, as sad as it will be, the “inevitable” will make it impossible to carry on, as understood from our discussions.
Oh well, I love those cranes that crush destroyed cars. Off to be retrained…