I'm not sure about that, because there is such a huge range of "need to work" lives. Taking it for granted that everything but "upper class" means "has to work

I'm not sure about that, because there is such a huge range of "need to work" lives. Taking it for granted that everything but "upper class" means "has to work", it's still worth drawing distinctions amongst the non-upper-classes. Those differences do exist in very meaningful ways, all the way down to life expectancy. You can't just trivialize away the difference between "college? how the fuck would I afford that?" and "it's 100% expected that I'll go, and my parents can pay the entire thing with zero debt".