In the US, I think that not doing the boring thing, which is spending time during 20s working or studying for a handful of career paths, climbing up the career ladder, saving up for downpayment for land in the richer areas of a handful of expensive cities, etc comes with huge costs.

The cost is that when you are 40 and you either have stable finances such that you can provide your kids with an acceptable amount of healthcare and education and housing stability, and you will be able to retire, or you get to 40 and you have to start sacrificing the goal of raising kids within the aforementioned parameters.

Maybe that is how it always was, it just wasn't a "known" thing so people didn't incorporate it into the decision making when they were 20.