The issue is two-fold - assuming that all the money comes at beginning, and forgetting about inflation, and not taking into account the shift in risk towards the later ten years, and assuming that your income stays the same. When taking into account the increase in income both absolute and in real terms after necessary expenses, you realize that a lot more than the majority of the money is invested in the latter 25 years.
But yes, it would be more than 20%, though a lot less than 130%.
"The average annual total return and compound annual growth rate of the S&P 500 index, including dividends, since inception in 1926 has been approximately 9.8%, or 6% after inflation" [0]. If you have a 40 year career, money you put in at the start would approximately be worth 10 times what you put in adjusting for inflation, and even money you put in midway would approximately be worth triple.
No, I came to my conclusion by putting away $100 every month for 40 years. $48000 is put in, $114000 is present at the end with a (historically unprecedented low) 4% overall return. Exactly the same amount of money is put away in the last 25 years as in the first 25 years.
The shift in risk should be accompanied by changes to the portfolio mix, of course.
But it's not how people save. The average person has too many expenses and not enough income at age 22 to save up as at age 45. And in those later years, the returns diminish.
Sure, if you have sufficient income to be able to save up enough for retirement just as soon as you get a job, that works. But that's not the reality for the average person. Most people don't get a high-paying job straight out of school.
I am not sure what you are arguing. Someone said that retirement works “on paper”, and you get 20% more. I pointed out that “on paper” you get more than double what you put in.
All of these other issues you raise have nothing to do with the financial illiteracy leading to the idea that you save for retirement just to get an incremental return rather than a multiple (or two, really, depending on timing) of what you put in. Perhaps if this were more well known, people would invest more at age 22.
tl;dr we’re talking about “on paper” here, investment works as advertised (In fact, much much better than the original poster believes it advertised). All of the things you bring up here are about scenarios that aren’t “on paper” any more.
But yes, it would be more than 20%, though a lot less than 130%.