20 years of talking to people about their finances says you are not underestimating.
My brother is 41. Never went to college. Just started working right out of high school, and has been with the same company for almost 20 years now. He owns his house outright, and has over 100 grand in the bank. He and his wife also own both of their cars outright that are each worth over 20 grand a piece, along with a decent 3rd car.
All this, yet he only has maybe 100 grand in his 401k. His company matches 6%, so he has been putting in 6% since day 1 so that he can get the full company match. He has never increased the amount.
He is a perfect example of someone who should have easily been able to retire at 50 or 55 if he has been taught even the basics about retirement planning, but there is no way that is going to be possible because he hasn't invested hardly anything. He is good with money in the sense that he saves and spends wisely. However, he is a complete novice when it comes to investing and/or retirement planning. He doesnt have the first clue what an index fund or mutual fund is.
I keep telling him to invest. He does not want to hear anything from me about it. I even advised him to just go see a financial planner for an assessment. Sort of the same concept where a lot of kids don't want to hear from their parents about it and could benefit quite a bit by hearing it from a teacher also.
The fact that a huge chunk of people can't retire is a major reason why things are crappy for people. If people stop giving all their money to credit card companies maybe they can retire at a decent age and open up some jobs for younger people, younger people who would hopefully have some basic knowledge of retirement planning which would benefit future generations as well.
If you are thinking about this in terms of just your own kids or yourself, you are missing the bigger picture completely.