What if you spent some of that time off in your 40s figuring out how to generate even more money for your 80s? You might not do that if you’re too busy spending 60 hours per week every week on your job.
What if you die at 55? Also possible.
Both models have their risks.
I understand why most people oversimplify and assume that waiting until the end of their lives to retire is the right way to do it. It seems safer, even though I’m not sure it is. Sometimes you outlive your money and sometimes the money outlives you.