Could you bear to wait eight more years for the 100%? You’ve already waited 62 years! What’s 8 more?

It's easy to think that way in your younger years. That's a much more difficult request for people actually in their 60's, lots of people make it to that age with broken down bodies, various illnesses/prescriptions/whatnot & probably can't see themselves continuing to do the work thing throughout their 60's let alone 70.

There's also the problem of holding down a job at that age, ageism exists in a lot of industries so a lot of these people are first in line for layoffs / taking a massive pay cut from their earlier jobs vs being a Walmart greeter or just being unemployed.

But sure... in theory if you manage to stay fit & healthy well into your old age & are able to hold onto your normal job then sure working into your 70's or more could be plausible. People probably worry less about that stuff once they're higher up on the corporate ladder - though at that point they should already have fat 401K plans & other investments so the social security aspect becomes less relevant.