I think you misunderstand the tendencies of mainstream music. It isn't that it is lagging behind, in fact looking to the past you see much more complicated and interesting song structures.
The more likely scenario is that pop music or mainstream music has trended away from anything too complicated. Aiming instead for reproduceable hits and music that is as least alienating as possible.
Every now and then an interesting song will make it to the pop stations, but it is rare.
Not to worry though, because you need only scratch past the surface to see that the music world (not industry) is alive, vibrant and more diverse and complex than ever.
The more likely scenario is that pop music or mainstream music has trended away from anything too complicated. Aiming instead for reproduceable hits and music that is as least alienating as possible.
Every now and then an interesting song will make it to the pop stations, but it is rare.
Not to worry though, because you need only scratch past the surface to see that the music world (not industry) is alive, vibrant and more diverse and complex than ever.