No, the problem was that increased contributions [that would've ensured solvency with lower market returns and/or extended life expectancy] would've cost more s

No, the problem was that increased contributions [that would've ensured solvency with lower market returns and/or extended life expectancy] would've cost more sooner, and no one wants to pay more. So, we "extend and pretend" using generous return assumptions and when those assumptions are not borne out in reality, we simply shrug. Similar to $39T in US treasuries someone will need to pay back. Only the top 40% of Americans have enough income to have a federal tax liability, so who is going to pay this debt back? Different sides of the same coin. What is a debt after all besides a promise to pay.