The 2000s were when tech and nerd culture really started to go mainstream. Windows XP, World of Warcraft, smartphones, the first good superhero movies (Iron Man), etc. The soundtrack IMO was a lot of nu-metal like Disturbed, Linkin Park, Avenged Sevenfold, and sadly even shit like Nickelback and Limp Bizkit. There was no one unified dress style, but it was around that time when Hot Topic was pretty popular, so a fair amount of black/goth.
The 2010s did start to feel a lot more like a grab bag of everything, everybody going their own way. Streaming (music, movies, shows) started really taking over, and that certainly contributed to individualist attitudes, along with the rise of social media giants. Then we got COVID to transition us into the 2020s, which feel right now like they might go similarly to the 1920s in a number of ways. Minus the flapper attire, anyway.