Since the proportion of GDP going to Social Security payments will go from 4% today to 7% (max) 40 years out (and stay there for the foreseeable future) -- when, 40 years out, average incomes should have doubled, leaving 186% (!) of today's average income to splurge on everything else (not even counting the free gifts of better technology for the same price!) -- if anything the retirement age in America (where the population is growing not shrinking -- the latter being real European problem) should be gradually lowered and benefits could be painlessly hiked. [disclosure: I am 63.]
The (non-complex) reality of the trust fund will become abundantly clear around 2017 when for the first time income tax will be used to cash "government owned bonds" to cover payroll tax shortfall.
This has happened before -- temporarily -- while waiting for Congress got around to a passing a modest increase in the payroll tax. This kind of -- temporary -- bridging a shortfall being a sensible purpose of even a (possibly much smaller) trust fund. On or around 2017 such bridging will become a permanent fixture -- the alternative being to begin raising payroll tax (I have heard) about one-tenth of one percent a year (as average income grows one and one-half percent a year).
While Social Security retirement is expected to soak up 7% of GDP, 40 years out, health care may take up 75% of GDP 80 years out (when average income -- which doubles every 40 years -- should have grown 400%). IOW, we would still have 100% of today's average income left over for everything else.
Per capita GDP grows 4 times as fast as population which is why Social Security was never a problem ( just what method you want to pay for it with) while health care costs are growing 5 times as fast as our ability to pay for it. Ergo, today's 15% of GDP spent on health care may grow to 20X (4 X 5) 80 years out -- 20 X the 15% of GDP soaked up by health care today or 300% of today's GDP, when GDP should have grown 400%.
The thing to do is get health care down to 200% of GDP, 80 years out, with Medicare for all (including underfunded Medicaid patients).