That you have no more neurones to understand or tell the differences don’t mean that there are no differences at all. Nu-metal was a big thing in the early 2000’s, along with the rising of electronic dance music, ambient music and intelligent dance music by the hands of those like Tiësto, Infected Mushroom, (who were one of the first duos of psytrance), Skream, Benga, Aphex Twin, amongst others. Then modern dubstep (badly called brostep), big room and electro house exploded in the 2010s, with post-dubstep (thanks to James Blake), metalcore, trap and the like giving their first steps too, and now since 2020 we’re seeing arise genres as color bass, the asian rock and pop scenes, hardwave, and more, and between 2010 and nowadays a LOT of more experimental and even bizarre genres (such as speedcore, extratone, 200step, glitch and so on).