Electronic music is and has always been an international phenomenon. Innovations happen due to cross-pollination of styles, not because specifically white Europeans "mature" it.
The Techno that blew up in Europe was initially imported from African Americans. Jungle/DNB was born out of mixing UK Hardcore with Jamaican Reggae/Dancehall/Dub music.
Footwork, Club, Bounce, Industrial, House, Electro, to name a few, are all styles that were prevalent on dancefloors in the US during the time you characterize it as "all about stale rehashes of guitar-based genres". All of these styles are woven into the DNA of the new underground generation. Nobody "owns" electronic music, and the scene is so much better when people stop claiming that anyone does.