Only recently, in human history, did the concept arise that each generation would be "better off financially" than the previous one. The idea that, if this happened once or twice, it should continue for eternity never had any statistical probability. I figure that some of my children have the potential to out-earn their father, and some don't. That's just reality.
Stepping from the general to the particular, one thing that happens is that children may have different values from their parents, and may not care about exceeding their parents' wealth. Beyond a median level of comfort, increases in income/wealth do not correlate with happier lives. Wealth is never sufficient for life satisfaction: there is always someone with more.
They could not be more wrong.
We have a God given right to our freedoms only.
Our standard of living is entirely dependent upon how willing we are to outwork and outcompete others.