I disagree. My DC are all young adults and I think there is definitely a style and trends. Post lockdown its leisurewear. Everything is much more casual now, its perfectly acceptable to wear a full tracksuit to dinner, crocs and sliders are acceptable but its all about the brands - among their friend group ethical brands are the trend and they would rather buy from tinted than from fast fashion stores. The body as a canvas is also much more mainstream, almost all of them have piercings and tattoos for example and people without any are the anomaly.
The way they consume music is different too - they rarely go to nightclubs favouring live music, whether local bands in the local pub or festivals. The artists they enjoy sing about mebtal health issues, battling addiction and gender fluidity.
Most of them dont drink anywhere near as much as i did at their age - they eat well, almost all go to the gym or play sports and they care about upf's and healthy eating and are concerned about the environment yet a huge number of them vape, which seems to be the new smoking, and they drink their coffee iced - its rare to see them have a hot drink.
They dont seem to watch much tv or go to the cinema, instead consuming content on social media or going to plays - their humour is alien to me but I think thats fairly typical. They also favour a more natural look, moving away from the massive eyebrows and contouring that came before them.
Just my take on living with young adults and spending time with young people