Should every generation be “better off” than the previous generation? What does “better off” mean? Looking only at the middle class and above, I’m assuming recent generations have been able to meet their core needs (sufficient housing, nutrition, healthcare, and education), so what should the current middle class be getting to reflect that they’re doing better than their parents? What I would classify as cool stuff: things like bigger houses, fancier gadgets, more exciting vacations. In other words, goods, services, and experiences that serve as markers of status.
Simplifying a bit, the point of status is to attract and keep mates. Higher status gives you more to choose from and greater commitment from those who have chosen you. When it comes to competition for mates, being better off than your parents isn’t much of a draw – being better than the current competition is.