They are part of the typical attire of working class lads, yes.
You say that like that statement wouldn't be more appropriate for those who make the poor a boogeyman.
There's no such thing as chav sub culture. The "chav" uniform of tracksuits and caps is just the standard attire of working class British lads.
It's the getup of the average white working class lad. Are you suggesting that the working class are all into drug-dealing?
Chav is a slur, not a subculture. It's derogatory shorthand for the white working class.
I didn't realise you couldn't post to multiple communities to get a wider array of answers, unless I'm misunderstanding you.
What is wrong with tracksuits, exactly?
It is the typical getup among white, working-class British lads, though. Just like in an American suburb, the typical getup would probably be something like a T-shirt and a pair of shorts.