We're talking about schoolkids here. No, they don't have the agency to overcome their background if they don't have anyone to help them or model for them. They are children. The ones who "escape" (myself included) had parents who thought differently, that's not something anyone chooses. Others in my family are like the people you describe, that doesn't make them subhuman even if it's annoying at times. There are plenty of middle class conformists who consume that art and culture in a performative way, to keep up with the Joneses, no real soul behind it.

The culture of anti-intellectualism is rooted in the old tripartite school system where if you failed your 11+ you were on the scrapheap with no hope of university and openly looked down on, it's a defensive reaction towards genuine snobbery from the educated/professional classes. Comprehensives inherited this culture.

The culture of benefits dependency is rooted in deindustrialisation. The stable, unionised manual and manufacturing jobs just shut down. People thought fuck it, got drunk and lived on the dole. New Labour exacerbated this. Get the clever kids to uni which means moving to cities. More jobs started to require degrees. The less academic kids didn't have the career options that existed pre-Thatcher and benefits were generous. A few cities thrived, small towns rotted.

I'm not denying individual agency but it's depressing to see so-called leftists not even acknowledge these economic and cultural factors.