[liability]

Yes, however the thing with safety nets is people typically avoid having to fall back on them. I could go broke and fall back to living with my elderly mother, but you can bet your ass I'd rather avoid that.

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.