It's kind of horrible and also completely unrealistic to expect people to work until 80.
When Social Security was created, average life expectancy for men was 58 and women 62, yet the retirement age was 65. By today’s life expectancy standards, 80 would be generous; we should probably raise the age to 85. Of course, I think most people would retire before then, but this would encourage them to boost their private savings to fund retirement.
The Silent Generation and Boomers have recast the purpose of Social Security (to their own benefit). Retirement with full benefits at the same ages - or with a two-year age difference - that people retired in 1930 is and never was realistic, given life expectancy.
Social Security should be a backstop only for the most vulnerable. And people should treat it for what it is - a tax, not an entitlement.