A rich kid might be able to ask their parents for more cash, but the embarassment and scolding that might come with that is likely enough to get a lot of rich kids to avoid the situation by choosing to live within the artificially imposed bounds of their allotted budget.
For me? There was no safety net. A year on food stamps, paying child support, working three jobs and being clinically depressed was me “figuring it out.”
At no time did they ever step in to help me financially. When I moved out for my freshman year was their idea of kicking me out of the nest.
I had one friend who feigned being broke because he would spend all his allowance before the next disbursement arrived. And would borrow money from friends.
In each case their job was assured. they were graduating into the family business or to manage its wealth. Or start their own business with financial help from the trust.
It's always a combination of wanting their kids to go through a phase of knowing what it's like to have nothing (teach the lesson of frugality), and making them spend their early 20's living hand-to-mouth as a way to maintain the illusion of control.
But that's not an indictment of modern culture. You see that pattern occur across generations.