Yeah, I think these rules (US) were made by people doing the math, without considering reality. It’s real easy to set aside a good amount to retire, as long as you set aside the recommended percentage throughout your career.

Of course the reality is that most of us will never do that. Many of us will get divorced and lose half what we put aside. Many of us will have financial emergencies such as medical emergencies, or being out of a job. Many of us will just be scraping by and can’t afford to set aside that much of our pay. Many of us just won’t have the perspective to be willing to set aside money for retirement many decades away. More importantly , most of us will hit those conditions sometime in our career and it’s just not realistic