It sounds like you're drawing arbitrary lines about what is and isn't a genre. House and metal have evolved various subgenres, to the point where some the subge

It sounds like you're drawing arbitrary lines about what is and isn't a genre. House and metal have evolved various subgenres, to the point where some the subgenres have their own festivals. Deadmau5 uses polymeters pretty extensively and rap/trap uses polyrhythms all the time. Yes there is a ton of electronic music and yes a lot of it sounds similar but there are new things coming out if you can dig through all the volume. A lot of the innovation is also in sound design and not necessarily composition.